diff --git a/Lectures/Lecture_01/Lecture.md b/Lectures/Lecture_01/Lecture.md
index cc783f28..257c0468 100644
--- a/Lectures/Lecture_01/Lecture.md
+++ b/Lectures/Lecture_01/Lecture.md
@@ -1,16 +1,10 @@
 ---
 title: ICS 01 - Introduction to C#, Visual Studio and .NET
-theme: simple
 css: _reveal-md/theme.css
+theme: simple
 separator: "^---$"
 verticalSeparator: "^\\+\\+\\+$"
-highlightTheme: vs
-progress: true
-slideNumber: true
-mouseWheel: false
-enableMenu: true
-enableChalkboard: true
-enableTitleFooter: true
+highlightTheme: "vs"
 ---
 
 
@@ -200,6 +194,45 @@ Team Explorer extension integrates GitFlow into your development workflow. It le
 
 <img src="assets/img/gitflow.png" width="40%">
 
++++
+
+### [Semantic Versioning 2.0.0](https://semver.org)
+
+Given a version number **MAJOR.MINOR.PATC**H, increment the:
+
+1. **MAJOR** version when you make incompatible API changes
+2. **MINOR** version when you add functionality in a backward compatible manner
+3. **PATCH** version when you make backward compatible bug fixes
+
+Additional labels for pre-release and build metadata are available as extensions to the MAJOR.MINOR.PATCH format.
+
++++
+
+### [semantic-release](https://semantic-release.gitbook.io/semantic-release/)
+
+semantic-release automates the whole package release workflow including: determining the next version number, generating the release notes, and publishing the package.
+
+This removes the immediate connection between human emotions and version numbers, strictly following the Semantic Versioning specification and communicating the impact of changes to consumers.
+
++++
+
+### [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/)
+
+```
+<type>[optional scope]: <description>
+
+[optional body]
+
+[optional footer(s)]
+```
+
+The commit contains the following structural elements, to communicate intent to the consumers of your library:
+
+1. *fix:* a commit of the type fix patches a bug in your codebase (this correlates with PATCH in Semantic Versioning).
+2. *feat:* a commit of the type feat introduces a new feature to the codebase (this correlates with MINOR in Semantic Versioning).
+3. *BREAKING CHANGE:* a commit that has a footer *BREAKING CHANGE:*, or appends a *!* after the type/scope, introduces a breaking API change (correlating with MAJOR in Semantic Versioning). A *BREAKING CHANGE* can be part of commits of any type.
+4. types other than *fix:* and *feat:* are allowed, for example @commitlint/config-conventional (based on the Angular convention) recommends *build:*, *chore:*, *ci:*, *docs:*, *style:*, *refactor:*, *perf:*, *test:*, and others.
+5. footers other than *BREAKING CHANGE:* <description> may be provided and follow a convention similar to git trailer format.
 
 ---
 ## Why To Choose .NET?
@@ -394,7 +427,7 @@ Team Explorer extension integrates GitFlow into your development workflow. It le
 ![](assets/img/csh.png)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/HelloWorld.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/HelloWorld.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 <!-- +++?code=assets/sln/Tests/HelloWorld.cs&lang=C#&title=Hello World Sample
 @[1]
@@ -739,7 +772,7 @@ int  cannotBeNull = null;      // Compile-time error
 ```
 
 +++
-<pre><code  data-sample='assets/sln/Tests/NullableType.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/NullableType.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Tests/NullableType.cs)
 
 
@@ -860,7 +893,7 @@ string s = "a" + 5; // a5
   * `int[][]` is a *single-dimensional array of single-dimensional* array of int
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Array.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Array.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- +++?code=assets/sln/Tests/Array.cs&lang=C#&title=Array Sample
 @[11-21] -->
 [Code sample](assets/sln/Tests/Array.cs)
@@ -978,7 +1011,7 @@ string s = "a" + 5; // a5
 | Boolean   | `false`       |
 
 +++
-<pre><code  data-sample='assets/sln/Tests/DefaultValue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/DefaultValue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[12-18] -->
 [Code sample](assets/sln/Tests/DefaultValue.cs)
 
@@ -995,22 +1028,22 @@ string s = "a" + 5; // a5
     * Variable **need not** *to be initialized* before the method call
 
 +++
-<pre><code  data-sample='assets/sln/Tests/ValueParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/ValueParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-26] -->
 [Code sample](assets/sln/Tests/ValueParameter.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/RefParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/RefParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-17] -->
 [Code sample](assets/sln/Tests/RefParameter.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/InParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/InParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-19] -->
 [Code sample](assets/sln/Tests/InParameter.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/OutParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/OutParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-24] -->
 [Code sample](assets/sln/Tests/OutParameter.cs)
 
@@ -1136,22 +1169,22 @@ x = y = 3;
 * Conditional (ternary) operand `?:`
 
 +++
-<pre><code  data-sample='assets/sln/Tests/If.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/If.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/If.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[13-30] -->
 [Code sample](assets/sln/Tests/Switch.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[45-64] -->
 [Code sample](assets/sln/Tests/Switch.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/TernaryOperand.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/TernaryOperand.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-12] -->
 [Code sample](assets/sln/Tests/TernaryOperand.cs)
 
@@ -1164,22 +1197,22 @@ x = y = 3;
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/While.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/While.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-16] -->
 [Code sample](assets/sln/Tests/While.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/DoWhile.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/DoWhile.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-15] -->
 [Code sample](assets/sln/Tests/DoWhile.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/For.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/For.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-13] -->
 [Code sample](assets/sln/Tests/For.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/ForEach.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/ForEach.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-14] -->
 [Code sample](assets/sln/Tests/ForEach.cs)
 
@@ -1194,28 +1227,28 @@ x = y = 3;
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Break.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Break.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-20] -->
 [Code sample](assets/sln/Tests/Break.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Continue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Continue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/Continue.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Return.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Return.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-12]
 @[17-20] -->
 [Code sample](assets/sln/Tests/Return.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Throw.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Throw.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-18] -->
 [Code sample](assets/sln/Tests/Throw.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Goto.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Goto.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/Goto.cs)
 
@@ -1228,12 +1261,12 @@ x = y = 3;
   * Simplification of a *Monitor synchronization primitive*
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Using.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Using.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-13] -->
 [Code sample](assets/sln/Tests/Using.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Lock.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Lock.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[11-22]
 @[24-35] -->
 [Code sample](assets/sln/Tests/Lock.cs)
diff --git a/Lectures/Lecture_01/_site/Lecture.html b/Lectures/Lecture_01/_site/Lecture.html
index 9021dbc3..51a81b04 100644
--- a/Lectures/Lecture_01/_site/Lecture.html
+++ b/Lectures/Lecture_01/_site/Lecture.html
@@ -399,7 +399,7 @@
 ![](assets/img/csh.png)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/HelloWorld.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/HelloWorld.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 <!-- +++?code=assets/sln/Tests/HelloWorld.cs&lang=C#&title=Hello World Sample
 @[1]
@@ -744,7 +744,7 @@
 ```
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/NullableType.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/NullableType.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Tests/NullableType.cs)
 
 
@@ -865,7 +865,7 @@
   * `int[][]` is a *single-dimensional array of single-dimensional* array of int
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Array.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Array.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- +++?code=assets/sln/Tests/Array.cs&lang=C#&title=Array Sample
 @[11-21] -->
 [Code sample](assets/sln/Tests/Array.cs)
@@ -983,7 +983,7 @@
 | Boolean   | `false`       |
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/DefaultValue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/DefaultValue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[12-18] -->
 [Code sample](assets/sln/Tests/DefaultValue.cs)
 
@@ -1000,22 +1000,22 @@
     * Variable **need not** *to be initialized* before the method call
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/ValueParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/ValueParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-26] -->
 [Code sample](assets/sln/Tests/ValueParameter.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/RefParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/RefParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-17] -->
 [Code sample](assets/sln/Tests/RefParameter.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/InParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/InParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-19] -->
 [Code sample](assets/sln/Tests/InParameter.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/OutParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/OutParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-24] -->
 [Code sample](assets/sln/Tests/OutParameter.cs)
 
@@ -1141,22 +1141,22 @@
 * Conditional (ternary) operand `?:`
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/If.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/If.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/If.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[13-30] -->
 [Code sample](assets/sln/Tests/Switch.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[45-64] -->
 [Code sample](assets/sln/Tests/Switch.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/TernaryOperand.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/TernaryOperand.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-12] -->
 [Code sample](assets/sln/Tests/TernaryOperand.cs)
 
@@ -1169,22 +1169,22 @@
 
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/While.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/While.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-16] -->
 [Code sample](assets/sln/Tests/While.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/DoWhile.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/DoWhile.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-15] -->
 [Code sample](assets/sln/Tests/DoWhile.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/For.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/For.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-13] -->
 [Code sample](assets/sln/Tests/For.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/ForEach.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/ForEach.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-14] -->
 [Code sample](assets/sln/Tests/ForEach.cs)
 
@@ -1199,28 +1199,28 @@
 
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Break.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Break.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-20] -->
 [Code sample](assets/sln/Tests/Break.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Continue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Continue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/Continue.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Return.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Return.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-12]
 @[17-20] -->
 [Code sample](assets/sln/Tests/Return.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Throw.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Throw.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-18] -->
 [Code sample](assets/sln/Tests/Throw.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Goto.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Goto.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/Goto.cs)
 
@@ -1233,12 +1233,12 @@
   * Simplification of a *Monitor synchronization primitive*
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Using.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Using.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-13] -->
 [Code sample](assets/sln/Tests/Using.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Lock.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Lock.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[11-22]
 @[24-35] -->
 [Code sample](assets/sln/Tests/Lock.cs)
diff --git a/Lectures/Lecture_01/_site/assets/sln/Tests/Tests.csproj b/Lectures/Lecture_01/_site/assets/sln/Tests/Tests.csproj
index 446019f6..df212723 100644
--- a/Lectures/Lecture_01/_site/assets/sln/Tests/Tests.csproj
+++ b/Lectures/Lecture_01/_site/assets/sln/Tests/Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <StartupObject>Tests.HelloWorld</StartupObject>
   </PropertyGroup>
 
diff --git a/Lectures/Lecture_01/_site/index.html b/Lectures/Lecture_01/_site/index.html
index 9021dbc3..51a81b04 100644
--- a/Lectures/Lecture_01/_site/index.html
+++ b/Lectures/Lecture_01/_site/index.html
@@ -399,7 +399,7 @@
 ![](assets/img/csh.png)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/HelloWorld.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/HelloWorld.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 <!-- +++?code=assets/sln/Tests/HelloWorld.cs&lang=C#&title=Hello World Sample
 @[1]
@@ -744,7 +744,7 @@
 ```
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/NullableType.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/NullableType.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Tests/NullableType.cs)
 
 
@@ -865,7 +865,7 @@
   * `int[][]` is a *single-dimensional array of single-dimensional* array of int
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Array.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Array.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- +++?code=assets/sln/Tests/Array.cs&lang=C#&title=Array Sample
 @[11-21] -->
 [Code sample](assets/sln/Tests/Array.cs)
@@ -983,7 +983,7 @@
 | Boolean   | `false`       |
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/DefaultValue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/DefaultValue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[12-18] -->
 [Code sample](assets/sln/Tests/DefaultValue.cs)
 
@@ -1000,22 +1000,22 @@
     * Variable **need not** *to be initialized* before the method call
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/ValueParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/ValueParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-26] -->
 [Code sample](assets/sln/Tests/ValueParameter.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/RefParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/RefParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-17] -->
 [Code sample](assets/sln/Tests/RefParameter.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/InParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/InParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-19] -->
 [Code sample](assets/sln/Tests/InParameter.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/OutParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/OutParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-24] -->
 [Code sample](assets/sln/Tests/OutParameter.cs)
 
@@ -1141,22 +1141,22 @@
 * Conditional (ternary) operand `?:`
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/If.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/If.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/If.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[13-30] -->
 [Code sample](assets/sln/Tests/Switch.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Switch.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[45-64] -->
 [Code sample](assets/sln/Tests/Switch.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/TernaryOperand.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/TernaryOperand.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-12] -->
 [Code sample](assets/sln/Tests/TernaryOperand.cs)
 
@@ -1169,22 +1169,22 @@
 
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/While.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/While.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-16] -->
 [Code sample](assets/sln/Tests/While.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/DoWhile.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/DoWhile.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-15] -->
 [Code sample](assets/sln/Tests/DoWhile.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/For.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/For.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-13] -->
 [Code sample](assets/sln/Tests/For.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/ForEach.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/ForEach.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-14] -->
 [Code sample](assets/sln/Tests/ForEach.cs)
 
@@ -1199,28 +1199,28 @@
 
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Break.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Break.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-20] -->
 [Code sample](assets/sln/Tests/Break.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Continue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Continue.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/Continue.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Return.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Return.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-12]
 @[17-20] -->
 [Code sample](assets/sln/Tests/Return.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Throw.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Throw.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-18] -->
 [Code sample](assets/sln/Tests/Throw.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Goto.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Goto.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/Goto.cs)
 
@@ -1233,12 +1233,12 @@
   * Simplification of a *Monitor synchronization primitive*
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Using.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Using.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-13] -->
 [Code sample](assets/sln/Tests/Using.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Lock.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Lock.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[11-22]
 @[24-35] -->
 [Code sample](assets/sln/Tests/Lock.cs)
diff --git a/Lectures/Lecture_01/assets/sln/Tests/Tests.csproj b/Lectures/Lecture_01/assets/sln/Tests/Tests.csproj
index 446019f6..c6f1ec8a 100644
--- a/Lectures/Lecture_01/assets/sln/Tests/Tests.csproj
+++ b/Lectures/Lecture_01/assets/sln/Tests/Tests.csproj
@@ -1,14 +1,14 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <StartupObject>Tests.HelloWorld</StartupObject>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.1" />
-    <PackageReference Include="xunit" Version="2.4.2" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
+    <PackageReference Include="xunit" Version="2.6.6" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
diff --git a/Lectures/Lecture_02/Lecture.md b/Lectures/Lecture_02/Lecture.md
index 472fc209..3f5332ab 100644
--- a/Lectures/Lecture_02/Lecture.md
+++ b/Lectures/Lecture_02/Lecture.md
@@ -1,16 +1,10 @@
 ---
-title: ICS 01 - Introduction to C#, Visual Studio and .NET
-theme: simple
+title: ICS 02 - Object-oriented Programming and Advanced Constructs in C#
 css: _reveal-md/theme.css
+theme: simple
 separator: "^---$"
 verticalSeparator: "^\\+\\+\\+$"
-highlightTheme: vs
-progress: true
-slideNumber: true
-mouseWheel: false
-enableMenu: true
-enableChalkboard: true
-enableTitleFooter: true
+highlightTheme: "vs"
 ---
 
 # Object-oriented Programming and Advanced Constructs in C#
@@ -30,7 +24,7 @@ enableTitleFooter: true
   * **Methods** and **fields** together create objects
 
 +++
-<pre><code data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-28] -->
 [Code sample](assets/sln/Examples/Dog.cs)
 
@@ -69,7 +63,7 @@ enableTitleFooter: true
 
 
 +++
-<pre><code  data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[12,17-21] -->
 [Code sample](assets/sln/Examples/Dog.cs)
 
@@ -87,15 +81,15 @@ enableTitleFooter: true
   * `base` - a reference to a *subtype* of a *super class*
 
 +++
-<pre><code  data-sample='assets/sln/Examples/Animal.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Animal.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Animal.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Examples/Pet.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Pet.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Pet.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-28] -->
 [Code sample](assets/sln/Examples/Dog.cs)
 
@@ -375,7 +369,7 @@ public string Name {
 * Constructors of the *base* class are accessible
 
 +++
-<pre><code  data-sample='assets/sln/Examples/Panda.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Panda.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Panda.cs)
 
 +++
@@ -399,15 +393,15 @@ public string Name {
   * `base` - refers to *base* class type instance
 
 +++
-<pre><code  data-sample='assets/sln/Examples/WildCat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/WildCat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/WildCat.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Examples/Cat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Cat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Cat.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Constructor.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Constructor.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-14] -->
 [Code sample](assets/sln/Tests/Constructor.cs)
 
@@ -431,7 +425,7 @@ Point p = new(3, 5);
   * Have one or more out parameters
 
 +++
-<pre><code  data-sample='assets/sln/Examples/Rectangle.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Rectangle.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Rectangle.cs)
 
 +++
@@ -549,7 +543,7 @@ public class Stock: Asset
 * Only *members* provided by given *base* class can be accessed through up-casted reference
 
 +++
-<pre><code  data-sample='assets/sln/Tests/UpCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/UpCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/UpCast.cs)
 
@@ -559,7 +553,7 @@ public class Stock: Asset
 * It **fails**, if *base* class instance is not compatible with *inherited* one
 
 +++
-<pre><code  data-sample='assets/sln/Tests/DownCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/DownCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[11-17]
 @[20-25] -->
 [Code sample](assets/sln/Tests/DownCast.cs)
@@ -570,7 +564,7 @@ public class Stock: Asset
 * Returns `null`, if failed
 
 +++
-<pre><code  data-sample='assets/sln/Tests/AsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/AsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-14] -->
 [Code sample](assets/sln/Tests/AsOperator.cs)
 
@@ -580,12 +574,12 @@ public class Stock: Asset
 * Usually before downcast
 
 +++
-<pre><code  data-sample='assets/sln/Tests/IsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/IsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-15] -->
 [Code sample](assets/sln/Tests/IsOperator.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/PatternMatching.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/PatternMatching.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-18]
 @[21-28] -->
 [Code sample](assets/sln/Tests/PatternMatching.cs)
@@ -999,7 +993,7 @@ Action<Derived> d = b;
   * You **cannot** assign an instance of `List<Base>` to a variable of type `List<Derived>` or vice versa.
 
 +++
-<pre><code  data-sample='assets/sln/Examples/CovarianceContravariance.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/CovarianceContravariance.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[11]
 @[27-30]
 @[33-36]
@@ -1014,7 +1008,7 @@ Action<Derived> d = b;
 * Values of value types are treated as objects by performing **boxing** and **unboxing** operations
 
 +++
-<pre><code  data-sample='assets/sln/Tests/Boxing.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Boxing.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-16] -->
 [Code sample](assets/sln/Tests/Boxing.cs)
 
@@ -1159,7 +1153,7 @@ class Test
 {
   static void Display(string name)
   {
-    if(name == null)
+    if(name is null)
       throw new ArgumentNullException(nameof(name));
     Console.WriteLine(name);
   }
diff --git a/Lectures/Lecture_02/_site/Lecture.html b/Lectures/Lecture_02/_site/Lecture.html
index d822b52c..ada0a669 100644
--- a/Lectures/Lecture_02/_site/Lecture.html
+++ b/Lectures/Lecture_02/_site/Lecture.html
@@ -35,7 +35,7 @@
   * **Methods** and **fields** together create objects
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-28] -->
 [Code sample](assets/sln/Examples/Dog.cs)
 
@@ -74,7 +74,7 @@
 
 
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-<pre><code  data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[12,17-21] -->
 [Code sample](assets/sln/Examples/Dog.cs)
 
@@ -92,15 +92,15 @@
   * `base` - a reference to a *subtype* of a *super class*
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Animal.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Animal.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Animal.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Pet.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Pet.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Pet.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-28] -->
 [Code sample](assets/sln/Examples/Dog.cs)
 
@@ -380,7 +380,7 @@
 * Constructors of the *base* class are accessible
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Panda.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Panda.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Panda.cs)
 
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@@ -404,15 +404,15 @@
   * `base` - refers to *base* class type instance
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/WildCat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/WildCat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/WildCat.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Cat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Cat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Cat.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Constructor.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Constructor.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-14] -->
 [Code sample](assets/sln/Tests/Constructor.cs)
 
@@ -436,7 +436,7 @@
   * Have one or more out parameters
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Rectangle.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Rectangle.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Rectangle.cs)
 
 </script></section><section data-markdown><script type="text/template">
@@ -554,7 +554,7 @@
 * Only *members* provided by given *base* class can be accessed through up-casted reference
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/UpCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/UpCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/UpCast.cs)
 
@@ -564,7 +564,7 @@
 * It **fails**, if *base* class instance is not compatible with *inherited* one
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/DownCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/DownCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[11-17]
 @[20-25] -->
 [Code sample](assets/sln/Tests/DownCast.cs)
@@ -575,7 +575,7 @@
 * Returns `null`, if failed
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/AsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/AsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-14] -->
 [Code sample](assets/sln/Tests/AsOperator.cs)
 
@@ -585,12 +585,12 @@
 * Usually before downcast
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/IsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/IsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-15] -->
 [Code sample](assets/sln/Tests/IsOperator.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/PatternMatching.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/PatternMatching.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-18]
 @[21-28] -->
 [Code sample](assets/sln/Tests/PatternMatching.cs)
@@ -1004,7 +1004,7 @@
   * You **cannot** assign an instance of `List<Base>` to a variable of type `List<Derived>` or vice versa.
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/CovarianceContravariance.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/CovarianceContravariance.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[11]
 @[27-30]
 @[33-36]
@@ -1019,7 +1019,7 @@
 * Values of value types are treated as objects by performing **boxing** and **unboxing** operations
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Boxing.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Boxing.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-16] -->
 [Code sample](assets/sln/Tests/Boxing.cs)
 
diff --git a/Lectures/Lecture_02/_site/assets/sln/Examples/Examples.csproj b/Lectures/Lecture_02/_site/assets/sln/Examples/Examples.csproj
index dbc15171..58990cd5 100644
--- a/Lectures/Lecture_02/_site/assets/sln/Examples/Examples.csproj
+++ b/Lectures/Lecture_02/_site/assets/sln/Examples/Examples.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
 </Project>
diff --git a/Lectures/Lecture_02/_site/assets/sln/Tests/Tests.csproj b/Lectures/Lecture_02/_site/assets/sln/Tests/Tests.csproj
index 62f676ed..a387680b 100644
--- a/Lectures/Lecture_02/_site/assets/sln/Tests/Tests.csproj
+++ b/Lectures/Lecture_02/_site/assets/sln/Tests/Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
 
     <IsPackable>false</IsPackable>
 
diff --git a/Lectures/Lecture_02/_site/index.html b/Lectures/Lecture_02/_site/index.html
index d822b52c..ada0a669 100644
--- a/Lectures/Lecture_02/_site/index.html
+++ b/Lectures/Lecture_02/_site/index.html
@@ -35,7 +35,7 @@
   * **Methods** and **fields** together create objects
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-28] -->
 [Code sample](assets/sln/Examples/Dog.cs)
 
@@ -74,7 +74,7 @@
 
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[12,17-21] -->
 [Code sample](assets/sln/Examples/Dog.cs)
 
@@ -92,15 +92,15 @@
   * `base` - a reference to a *subtype* of a *super class*
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Animal.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Animal.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Animal.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Pet.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Pet.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Pet.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Dog.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-28] -->
 [Code sample](assets/sln/Examples/Dog.cs)
 
@@ -380,7 +380,7 @@
 * Constructors of the *base* class are accessible
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Panda.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Panda.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Panda.cs)
 
 </script></section><section data-markdown><script type="text/template">
@@ -404,15 +404,15 @@
   * `base` - refers to *base* class type instance
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/WildCat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/WildCat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/WildCat.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Cat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Cat.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Cat.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Constructor.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Constructor.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-14] -->
 [Code sample](assets/sln/Tests/Constructor.cs)
 
@@ -436,7 +436,7 @@
   * Have one or more out parameters
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/Rectangle.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/Rectangle.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](assets/sln/Examples/Rectangle.cs)
 
 </script></section><section data-markdown><script type="text/template">
@@ -554,7 +554,7 @@
 * Only *members* provided by given *base* class can be accessed through up-casted reference
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/UpCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/UpCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17] -->
 [Code sample](assets/sln/Tests/UpCast.cs)
 
@@ -564,7 +564,7 @@
 * It **fails**, if *base* class instance is not compatible with *inherited* one
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/DownCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/DownCast.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[11-17]
 @[20-25] -->
 [Code sample](assets/sln/Tests/DownCast.cs)
@@ -575,7 +575,7 @@
 * Returns `null`, if failed
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/AsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/AsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-14] -->
 [Code sample](assets/sln/Tests/AsOperator.cs)
 
@@ -585,12 +585,12 @@
 * Usually before downcast
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/IsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/IsOperator.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-15] -->
 [Code sample](assets/sln/Tests/IsOperator.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/PatternMatching.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/PatternMatching.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-18]
 @[21-28] -->
 [Code sample](assets/sln/Tests/PatternMatching.cs)
@@ -1004,7 +1004,7 @@
   * You **cannot** assign an instance of `List<Base>` to a variable of type `List<Derived>` or vice versa.
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Examples/CovarianceContravariance.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/CovarianceContravariance.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[11]
 @[27-30]
 @[33-36]
@@ -1019,7 +1019,7 @@
 * Values of value types are treated as objects by performing **boxing** and **unboxing** operations
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Tests/Boxing.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/Boxing.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-16] -->
 [Code sample](assets/sln/Tests/Boxing.cs)
 
diff --git a/Lectures/Lecture_02/assets/sln/Examples/Examples.csproj b/Lectures/Lecture_02/assets/sln/Examples/Examples.csproj
index dbc15171..58990cd5 100644
--- a/Lectures/Lecture_02/assets/sln/Examples/Examples.csproj
+++ b/Lectures/Lecture_02/assets/sln/Examples/Examples.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
 </Project>
diff --git a/Lectures/Lecture_02/assets/sln/Tests/Tests.csproj b/Lectures/Lecture_02/assets/sln/Tests/Tests.csproj
index 62f676ed..a387680b 100644
--- a/Lectures/Lecture_02/assets/sln/Tests/Tests.csproj
+++ b/Lectures/Lecture_02/assets/sln/Tests/Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
 
     <IsPackable>false</IsPackable>
 
diff --git a/Lectures/Lecture_03/Lecture.md b/Lectures/Lecture_03/Lecture.md
index c178a7ff..94264971 100644
--- a/Lectures/Lecture_03/Lecture.md
+++ b/Lectures/Lecture_03/Lecture.md
@@ -1,16 +1,10 @@
 ---
-title: ICS 01 - Introduction to C#, Visual Studio and .NET
-theme: simple
+title: ICS 03 - .NET Standard and Language Integrated Query (LINQ)
 css: _reveal-md/theme.css
+theme: simple
 separator: "^---$"
 verticalSeparator: "^\\+\\+\\+$"
-highlightTheme: vs
-progress: true
-slideNumber: true
-mouseWheel: false
-enableMenu: true
-enableChalkboard: true
-enableTitleFooter: true
+highlightTheme: "vs"
 ---
 
 # .NET Standard and Language Integrated Query (LINQ)
@@ -196,7 +190,7 @@ catch (System.OverflowException) {
 ```
 
 +++
-<pre><code  data-sample='assets/sln/Tests/ConvertTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/ConvertTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-21]
 @[12,17]
 @[13,18]
@@ -221,7 +215,7 @@ Console.WriteLine(BitConverter.ToString(sampleByteArray)); //01
 ```
 
 +++
-<pre><code  data-sample='assets/sln/Tests/BitConverterTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/BitConverterTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-16]
 @[11]
 @[12]
@@ -280,7 +274,7 @@ WebRequest webRequest = WebRequest.Create(uri);
 ```
 
 +++
-<pre><code  data-sample='assets/sln/Tests/UriTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/UriTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-15]
 @[11,12]
 @[14]
@@ -306,7 +300,7 @@ Console.ReadLine();
 ```
 
 +++
-<pre><code  data-sample='assets/sln/Examples/ConsoleSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/ConsoleSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-20]
 @[9]
 @[11-12,19]
@@ -515,7 +509,7 @@ delegate TResult Func<in T1,in T2,out TResult>(T1 arg1, T2 arg2); //has two para
   * Defines **non-generic collection** of objects that can be individually accessed by index
 
 +++
-<pre><code  data-sample='assets/sln/Examples/ArrayListSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/ArrayListSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-25]
 @[11-14]
 @[17-19]
@@ -535,7 +529,7 @@ delegate TResult Func<in T1,in T2,out TResult>(T1 arg1, T2 arg2); //has two para
   * Exposes an *enumerator*, which supports a simple iteration over a non-generic collection
 
 +++
-<pre><code  data-sample='assets/sln/Examples/StackSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/StackSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-24]
 @[11-14]
 @[17-18]
@@ -551,7 +545,7 @@ delegate TResult Func<in T1,in T2,out TResult>(T1 arg1, T2 arg2); //has two para
 * Implements the `IEnumerable` interface
 
 +++
-<pre><code  data-sample='assets/sln/Examples/QueueSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/QueueSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-24]
 @[11-14]
 @[17-18]
@@ -568,7 +562,7 @@ delegate TResult Func<in T1,in T2,out TResult>(T1 arg1, T2 arg2); //has two para
   * Nongeneric collection of key/value pairs
 
 +++
-<pre><code  data-sample='assets/sln/Tests/HashtableTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/HashtableTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-24]
 @[13, 17-21]
 @[22]
@@ -630,7 +624,7 @@ sortedList.Add("First", "Hello");
   * `class IComparer<T>`
 
 +++
-<pre><code  data-sample='assets/sln/Tests/GenericListTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/GenericListTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-18]
 @[21-27]
 @[30-36]
@@ -646,7 +640,7 @@ sortedList.Add("First", "Hello");
   * Instances of the **same specified type**
 
 +++
-<pre><code  data-sample='assets/sln/Tests/GenericStackTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/GenericStackTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-19]
 @[11-16]
 @[18]
@@ -661,7 +655,7 @@ sortedList.Add("First", "Hello");
 * Collection of instances of the **same specified type**
 
 +++
-<pre><code  data-sample='assets/sln/Tests/GenericQueueTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/GenericQueueTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-19]
 @[11-16]
 @[18]
@@ -685,7 +679,7 @@ sortedList.Add("First", "Hello");
   * `TValue` - the type of the values in the dictionary
 
 +++
-<pre><code  data-sample='assets/sln/Tests/GenericDictionaryTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/GenericDictionaryTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-20]
 @[11-16]
 @[18-19]
@@ -771,7 +765,7 @@ Console.WriteLine($"{Path.GetTempFileName()} is a file available for use.");
   * Creation of `FileStream` objects
 
 +++
-<pre><code  data-sample='assets/sln/Examples/DirectorySample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/DirectorySample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-21]
 @[10-11]
 @[13-20]
@@ -779,7 +773,7 @@ Console.WriteLine($"{Path.GetTempFileName()} is a file available for use.");
 [Code sample](assets/sln/Examples/DirectorySample.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Examples/FileSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/FileSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-16]
 @[10]
 @[12-13]
@@ -800,7 +794,7 @@ Console.WriteLine($"{Path.GetTempFileName()} is a file available for use.");
   * Creation of `FileStream` objects
 
 +++
-<pre><code  data-sample='assets/sln/Examples/DirectoryInfoSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/DirectoryInfoSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[8-34]
 @[10-11]
 @[12-13,29-33]
@@ -811,7 +805,7 @@ Console.WriteLine($"{Path.GetTempFileName()} is a file available for use.");
 [Code sample](assets/sln/Examples/DirectoryInfoSample.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Examples/FileInfoSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/FileInfoSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -862,7 +856,7 @@ using (FileStream fileStream = File.OpenRead(@"c:\test.txt"))
 * In a **particular encoding**
 
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-<pre><code  data-sample='assets/sln/Examples/StreamWriterSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/StreamWriterSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -871,7 +865,7 @@ using (FileStream fileStream = File.OpenRead(@"c:\test.txt"))
 [Code sample](assets/sln/Examples/StreamWriterSample.cs)
 
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-<pre><code  data-sample='assets/sln/Examples/StreamReaderSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/StreamReaderSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -903,7 +897,7 @@ using (FileStream fileStream = File.OpenRead(@"c:\test.txt"))
   * `class AnonymousPipeClientStream` - client side of an anonymous pipe stream
 
 +++
-<pre><code  data-sample='assets/sln/Examples/PipeServerSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/PipeServerSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 [Code sample](assets/sln/Examples/PipeServerSample.cs)
 
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-<pre><code  data-sample='assets/sln/Examples/PipeClientSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/PipeClientSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -979,7 +973,7 @@ Console.WriteLine(c5);
 * **Manipulate instances of loaded types**
 
 +++
-<pre><code  data-sample='assets/sln/Tests/ReflectionTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/ReflectionTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1010,7 +1004,7 @@ x.FakeMethod();
 
 
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-<pre><code  data-sample='assets/sln/Examples/DynamicParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/DynamicParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1064,7 +1058,7 @@ x.FakeMethod();
 
 
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-<pre><code  data-sample='assets/sln/Examples/EncodingSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/EncodingSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1096,7 +1090,7 @@ x.FakeMethod();
 
 
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-<pre><code  data-sample='assets/sln/Tests/StringBuilderTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/StringBuilderTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1134,7 +1128,7 @@ x.FakeMethod();
 
 
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-<pre><code  data-sample='assets/sln/Tests/RegexTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/RegexTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1224,7 +1218,7 @@ var query = from m in musos
 
 
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-<pre><code  data-sample='assets/sln/Tests/LinqMaterializationTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqMaterializationTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1256,7 +1250,7 @@ Filtering is an operation to restrict the result set to the point where it shows
 ![](assets/img/LINQ/LINQ_OfType.png)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqFilteringOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqFilteringOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ![](assets/img/LINQ/LINQ_Join.png)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqJoinOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqJoinOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1311,7 +1305,7 @@ Projection is an operation in which an object is transformed into an altogether
 ![](assets/img/LINQ/LINQ_SelectMany.png)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqProjectionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqProjectionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1339,7 +1333,7 @@ A sorting operation allows ordering the elements of a sequence on basis of a sin
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqSortingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqSortingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1372,7 +1366,7 @@ The operators put data into some groups based on a common shared attribute.
 ![ToLookup](assets/img/LINQ/LINQ_ToLookup.png)
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqGroupingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqGroupingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-29]
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@@ -1402,7 +1396,7 @@ The operators change the type of input objects and are used in a diverse range o
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqConversionsOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqConversionsOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[13-20]
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@@ -1450,7 +1444,7 @@ Performs concatenation of two sequences and is quite similar to the Union operat
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqConcatenationOperatorTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqConcatenationOperatorTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1474,7 +1468,7 @@ Performs any type of desired aggregation and allows creating custom aggregations
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqAggregationOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqAggregationOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[10-17]
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@@ -1525,7 +1519,7 @@ These operators return a Boolean value when some or all elements within a sequen
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqQuantifierOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqQuantifierOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1554,7 +1548,7 @@ Divide an input sequence into two parts without rearranging the elements of the
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqPartitionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqPartitionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1590,7 +1584,7 @@ A new sequence of values is created by generational operators.
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqGenerationOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqGenerationOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1624,7 +1618,7 @@ There are four operators for the set operations, each yielding a result based on
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqSetOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqSetOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1657,7 +1651,7 @@ Compares two sequences (enumerable) and determines if they are an exact match or
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqEqualityOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqEqualityOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1690,7 +1684,7 @@ All standard query element operators return a single element from a collection.
 
 
 +++
-<pre><code  data-sample='assets/sln/Tests/LinqElementOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqElementOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1867,7 +1861,7 @@ Connection: System.Data.SqlClient.SqlConnection
   * Writer provides way to **generate streams or files** that contain XML data
 
 +++
-<pre><code  data-sample='assets/sln/Examples/XmlReaderSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlReaderSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1878,7 +1872,7 @@ Connection: System.Data.SqlClient.SqlConnection
 
 
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-<pre><code  data-sample='assets/sln/Examples/XmlDocumentReadSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlDocumentReadSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XmlWriterSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlWriterSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XmlDocumentWriteSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlDocumentWriteSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XPathSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XPathSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XmlSerialization.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlSerialization.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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diff --git a/Lectures/Lecture_03/_site/Lecture.html b/Lectures/Lecture_03/_site/Lecture.html
index 045793bf..72481ff6 100644
--- a/Lectures/Lecture_03/_site/Lecture.html
+++ b/Lectures/Lecture_03/_site/Lecture.html
@@ -201,7 +201,7 @@
 ```
 
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-<pre><code  data-sample='assets/sln/Tests/ConvertTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/ConvertTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ```
 
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-<pre><code  data-sample='assets/sln/Tests/BitConverterTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ```
 
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-<pre><code  data-sample='assets/sln/Tests/UriTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ```
 
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-<pre><code  data-sample='assets/sln/Examples/ConsoleSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * Defines **non-generic collection** of objects that can be individually accessed by index
 
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-<pre><code  data-sample='assets/sln/Examples/ArrayListSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * Exposes an *enumerator*, which supports a simple iteration over a non-generic collection
 
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-<pre><code  data-sample='assets/sln/Examples/StackSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 * Implements the `IEnumerable` interface
 
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-<pre><code  data-sample='assets/sln/Examples/QueueSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/QueueSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * Nongeneric collection of key/value pairs
 
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-<pre><code  data-sample='assets/sln/Tests/HashtableTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * `class IComparer<T>`
 
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-<pre><code  data-sample='assets/sln/Tests/GenericListTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/GenericListTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * Instances of the **same specified type**
 
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-<pre><code  data-sample='assets/sln/Tests/GenericStackTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 * Collection of instances of the **same specified type**
 
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-<pre><code  data-sample='assets/sln/Tests/GenericQueueTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/GenericQueueTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * `TValue` - the type of the values in the dictionary
 
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-<pre><code  data-sample='assets/sln/Tests/GenericDictionaryTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/GenericDictionaryTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * Creation of `FileStream` objects
 
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-<pre><code  data-sample='assets/sln/Examples/DirectorySample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/DirectorySample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/FileSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * Creation of `FileStream` objects
 
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-<pre><code  data-sample='assets/sln/Examples/DirectoryInfoSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/DirectoryInfoSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/FileInfoSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 * In a **particular encoding**
 
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 [Code sample](assets/sln/Examples/StreamWriterSample.cs)
 
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   * `class AnonymousPipeClientStream` - client side of an anonymous pipe stream
 
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-<pre><code  data-sample='assets/sln/Examples/PipeServerSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 [Code sample](assets/sln/Examples/PipeServerSample.cs)
 
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-<pre><code  data-sample='assets/sln/Examples/PipeClientSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 * **Manipulate instances of loaded types**
 
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-<pre><code  data-sample='assets/sln/Tests/ReflectionTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/ReflectionTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/DynamicParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/DynamicParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/EncodingSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/EncodingSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/StringBuilderTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/StringBuilderTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/RegexTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/RegexTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqMaterializationTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqMaterializationTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ![](assets/img/LINQ/LINQ_OfType.png)
 
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-<pre><code  data-sample='assets/sln/Tests/LinqFilteringOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ![](assets/img/LINQ/LINQ_Join.png)
 
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-<pre><code  data-sample='assets/sln/Tests/LinqJoinOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqJoinOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ![](assets/img/LINQ/LINQ_SelectMany.png)
 
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-<pre><code  data-sample='assets/sln/Tests/LinqProjectionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqProjectionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqSortingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqSortingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ![ToLookup](assets/img/LINQ/LINQ_ToLookup.png)
 
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-<pre><code  data-sample='assets/sln/Tests/LinqGroupingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqGroupingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqConversionsOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqConversionsOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqConcatenationOperatorTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqConcatenationOperatorTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqAggregationOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqAggregationOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqQuantifierOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqQuantifierOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqPartitionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqPartitionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqGenerationOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqGenerationOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqSetOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqSetOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqEqualityOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqEqualityOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqElementOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqElementOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * Writer provides way to **generate streams or files** that contain XML data
 
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-<pre><code  data-sample='assets/sln/Examples/XmlReaderSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlReaderSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XmlDocumentReadSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlDocumentReadSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XmlWriterSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlWriterSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XmlDocumentWriteSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlDocumentWriteSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XPathSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XPathSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XmlSerialization.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlSerialization.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-12]
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diff --git a/Lectures/Lecture_03/_site/assets/sln/Tests/LinqGenerationOperationsTest.cs b/Lectures/Lecture_03/_site/assets/sln/Tests/LinqGenerationOperationsTest.cs
index 3f84b8fc..9054ea49 100644
--- a/Lectures/Lecture_03/_site/assets/sln/Tests/LinqGenerationOperationsTest.cs
+++ b/Lectures/Lecture_03/_site/assets/sln/Tests/LinqGenerationOperationsTest.cs
@@ -12,9 +12,9 @@ public void DefaultIfEmptyTest()
             int[] emptyInt = { };
             string[] words = { "one", "two", "three" };
 
-            Assert.True(emptyStr.DefaultIfEmpty().First() == null);
+            Assert.True(emptyStr.DefaultIfEmpty().First() is null);
             Assert.True(emptyInt.DefaultIfEmpty().First() == 0);
-            Assert.False(words.DefaultIfEmpty() == null);
+            Assert.False(words.DefaultIfEmpty() is null);
         }
 
         [Fact]
diff --git a/Lectures/Lecture_03/_site/index.html b/Lectures/Lecture_03/_site/index.html
index 045793bf..72481ff6 100644
--- a/Lectures/Lecture_03/_site/index.html
+++ b/Lectures/Lecture_03/_site/index.html
@@ -201,7 +201,7 @@
 ```
 
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-<pre><code  data-sample='assets/sln/Tests/ConvertTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/ConvertTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ```
 
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-<pre><code  data-sample='assets/sln/Tests/BitConverterTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/BitConverterTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ```
 
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-<pre><code  data-sample='assets/sln/Tests/UriTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/UriTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ```
 
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-<pre><code  data-sample='assets/sln/Examples/ConsoleSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/ConsoleSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/ArrayListSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/ArrayListSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/StackSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/StackSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 * Implements the `IEnumerable` interface
 
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-<pre><code  data-sample='assets/sln/Examples/QueueSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/QueueSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * Nongeneric collection of key/value pairs
 
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-<pre><code  data-sample='assets/sln/Tests/HashtableTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/HashtableTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/GenericListTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/GenericListTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * Instances of the **same specified type**
 
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-<pre><code  data-sample='assets/sln/Tests/GenericStackTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/GenericStackTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 * Collection of instances of the **same specified type**
 
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-<pre><code  data-sample='assets/sln/Tests/GenericQueueTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/GenericQueueTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * `TValue` - the type of the values in the dictionary
 
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-<pre><code  data-sample='assets/sln/Tests/GenericDictionaryTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/GenericDictionaryTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/DirectorySample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/DirectorySample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/FileSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/FileSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * Creation of `FileStream` objects
 
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-<pre><code  data-sample='assets/sln/Examples/DirectoryInfoSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/DirectoryInfoSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -816,7 +816,7 @@
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-<pre><code  data-sample='assets/sln/Examples/FileInfoSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/FileInfoSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -867,7 +867,7 @@
 * In a **particular encoding**
 
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-<pre><code  data-sample='assets/sln/Examples/StreamWriterSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/StreamWriterSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -876,7 +876,7 @@
 [Code sample](assets/sln/Examples/StreamWriterSample.cs)
 
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-<pre><code  data-sample='assets/sln/Examples/StreamReaderSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/StreamReaderSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/ReflectionTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/DynamicParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/DynamicParameter.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/EncodingSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/StringBuilderTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/RegexTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqMaterializationTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqMaterializationTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ![](assets/img/LINQ/LINQ_OfType.png)
 
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-<pre><code  data-sample='assets/sln/Tests/LinqFilteringOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqJoinOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqJoinOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ![](assets/img/LINQ/LINQ_SelectMany.png)
 
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-<pre><code  data-sample='assets/sln/Tests/LinqProjectionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqProjectionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqSortingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqSortingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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 ![ToLookup](assets/img/LINQ/LINQ_ToLookup.png)
 
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-<pre><code  data-sample='assets/sln/Tests/LinqGroupingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqGroupingOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqConversionsOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqConversionsOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqConcatenationOperatorTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqConcatenationOperatorTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqAggregationOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqAggregationOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqQuantifierOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqQuantifierOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqPartitionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqPartitionOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqGenerationOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqGenerationOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqSetOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqSetOperationsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqEqualityOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqEqualityOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Tests/LinqElementOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Tests/LinqElementOperatorsTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * Writer provides way to **generate streams or files** that contain XML data
 
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-<pre><code  data-sample='assets/sln/Examples/XmlReaderSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlReaderSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XmlDocumentReadSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlDocumentReadSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XmlWriterSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlWriterSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XmlDocumentWriteSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlDocumentWriteSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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-<pre><code  data-sample='assets/sln/Examples/XPathSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XPathSample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1979,7 +1979,7 @@
 
 
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-<pre><code  data-sample='assets/sln/Examples/XmlSerialization.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/XmlSerialization.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[7-12]
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diff --git a/Lectures/Lecture_03/assets/sln/Tests/LinqGenerationOperationsTest.cs b/Lectures/Lecture_03/assets/sln/Tests/LinqGenerationOperationsTest.cs
index 3f84b8fc..9054ea49 100644
--- a/Lectures/Lecture_03/assets/sln/Tests/LinqGenerationOperationsTest.cs
+++ b/Lectures/Lecture_03/assets/sln/Tests/LinqGenerationOperationsTest.cs
@@ -12,9 +12,9 @@ public void DefaultIfEmptyTest()
             int[] emptyInt = { };
             string[] words = { "one", "two", "three" };
 
-            Assert.True(emptyStr.DefaultIfEmpty().First() == null);
+            Assert.True(emptyStr.DefaultIfEmpty().First() is null);
             Assert.True(emptyInt.DefaultIfEmpty().First() == 0);
-            Assert.False(words.DefaultIfEmpty() == null);
+            Assert.False(words.DefaultIfEmpty() is null);
         }
 
         [Fact]
diff --git a/Lectures/Lecture_04/Lecture.md b/Lectures/Lecture_04/Lecture.md
index 0f485901..056835db 100644
--- a/Lectures/Lecture_04/Lecture.md
+++ b/Lectures/Lecture_04/Lecture.md
@@ -1,16 +1,10 @@
 ---
 title: ICS 04 - Data Persistence in .NET Applications
-theme: simple
 css: _reveal-md/theme.css
+theme: simple
 separator: "^---$"
 verticalSeparator: "^\\+\\+\\+$"
-highlightTheme: vs
-progress: true
-slideNumber: true
-mouseWheel: false
-enableMenu: true
-enableChalkboard: true
-enableTitleFooter: true
+highlightTheme: "vs"
 ---
 
 # Persistence
@@ -270,7 +264,7 @@ enableTitleFooter: true
 
 +++
 
-<pre><code  data-sample='assets/sln/Examples/SqlClientExample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/SqlClientExample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- +++?code=assets/sln/Examples/SqlClientExample.cs&lang=C#&title=ADO.NET SqlClient Sample
 @[10-53]
 @[10-12]
@@ -500,7 +494,7 @@ public class SchoolDbContext : DbContext
         * Represents multiplicity of many (*)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
@@ -538,7 +532,7 @@ protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
   5. Each collection **property** must be `ICollection<T>`
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityTypesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityTypesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 <!-- +++?code=assets/sln/EntityFramework/School.DAL.Tests/EntityTypesTest.cs&lang=C#&title=Entity Types Sample
 @[13-21]
@@ -567,7 +561,7 @@ protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
 * Other changes must be made **explicitly using** proper **methods of **`DbContext`** or **`DbSet`
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityStatesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityStatesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 <!-- +++?code=assets/sln/EntityFramework/School.DAL.Tests/EntityStatesTest.cs&lang=C#&title=Entity States Sample
 @[12-24]
@@ -661,16 +655,16 @@ public class MSSQLLocalDBDbContextFactory : IDbContextFactory
 ```
 
 +++
-<pre><code  data-sample='assets/sln/Dapper.DAL/appconfig.json' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Dapper.DAL/appconfig.json' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/appconfig.json)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/SchoolDbContext.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/SchoolDbContext.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-30] -->
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/SchoolDbContext.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL.Tests/LinqLazyEvaluationTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL.Tests/LinqLazyEvaluationTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[13-21]
 @[23-34] -->
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL.Tests/LinqLazyEvaluationTest.cs)
@@ -1042,11 +1036,11 @@ modelBuilder.Entity<StudentEntity>()
 ```
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/AddressEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/AddressEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/AddressEntity.cs)
 
 +++
@@ -1117,11 +1111,11 @@ public class Grade
 ```
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/GradeEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/GradeEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/GradeEntity.cs)
 
 +++
@@ -1148,15 +1142,15 @@ modelBuilder.Entity<StudentCourse>()
 ```
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/CourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/CourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/CourseEntity.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentCourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentCourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentCourseEntity.cs)
 
 
@@ -1219,11 +1213,11 @@ var students = context.Students
   3. *Pass query as a parameter in Execute method*
 
 +++
-<pre><code  data-sample='assets/sln/Dapper.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Dapper.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/Dapper.DAL/Entities/StudentEntity.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Dapper.DAL/StudentRepository.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Dapper.DAL/StudentRepository.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1231,7 +1225,7 @@ var students = context.Students
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/Dapper.DAL/StudentRepository.cs)
 
 +++
-<pre><code  data-sample='assets/sln/Dapper.DAL.Tests/StudentRepositoryTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Dapper.DAL.Tests/StudentRepositoryTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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@@ -1530,7 +1524,7 @@ public class Dapper : ITestSignature
   * **UnitOfWork** design pattern
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs)
 
 ---
@@ -1541,7 +1535,7 @@ public class Dapper : ITestSignature
 ![](assets/img/UnitOfWork.jpg)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/UnitOfWork/UnitOfWork.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/UnitOfWork/UnitOfWork.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/UnitOfWork/UnitOfWork.cs)
 
 ---
@@ -1597,27 +1591,27 @@ var topSellingCourses = schoolCourses.Where(c => c.IsPublic && c.IsApproved).Ord
   * Represents the **actual data and information**
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Mappers/IMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Mappers/IMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/IMapper.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/AddressDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/AddressDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/DetailModels/AddressDetailModel.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Models/ListModels/StudentListModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Models/ListModels/StudentListModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Models/ListModels/StudentListModel.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/StudentDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/StudentDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Models/DetailModels/StudentDetailModel.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs)
 
 ---
@@ -1724,17 +1718,17 @@ config.AssertConfigurationIsValid();
   * Have no knowledge of the facade and keep no reference to it
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Facades/CrudFacadeBase.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Facades/CrudFacadeBase.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Facades/CrudFacadeBase.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL.Tests/AddressFacadeTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL.Tests/AddressFacadeTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL.Tests/AddressFacadeTests.cs)
 
 +++
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL.Tests/StudentFacadeTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL.Tests/StudentFacadeTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL.Tests/StudentFacadeTests.cs)
 
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diff --git a/Lectures/Lecture_04/_site/Lecture.html b/Lectures/Lecture_04/_site/Lecture.html
index 3fc3f8ce..d5997d64 100644
--- a/Lectures/Lecture_04/_site/Lecture.html
+++ b/Lectures/Lecture_04/_site/Lecture.html
@@ -275,7 +275,7 @@
 
 </script></section><section data-markdown><script type="text/template">
 
-<pre><code  data-sample='assets/sln/Examples/SqlClientExample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/SqlClientExample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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         * Represents multiplicity of many (*)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
@@ -543,7 +543,7 @@
   5. Each collection **property** must be `ICollection<T>`
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityTypesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityTypesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
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 * Other changes must be made **explicitly using** proper **methods of **`DbContext`** or **`DbSet`
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityStatesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityStatesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 <!-- +++?code=assets/sln/EntityFramework/School.DAL.Tests/EntityStatesTest.cs&lang=C#&title=Entity States Sample
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@@ -666,16 +666,16 @@
 ```
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Dapper.DAL/appconfig.json' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Dapper.DAL/appconfig.json' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/appconfig.json)
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/SchoolDbContext.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/SchoolDbContext.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL.Tests/LinqLazyEvaluationTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[13-21]
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 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL.Tests/LinqLazyEvaluationTest.cs)
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 ```
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/AddressEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/AddressEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/AddressEntity.cs)
 
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 ```
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/GradeEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/GradeEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/GradeEntity.cs)
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/CourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/CourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/CourseEntity.cs)
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentCourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentCourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentCourseEntity.cs)
 
 
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   3. *Pass query as a parameter in Execute method*
 
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 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/Dapper.DAL/Entities/StudentEntity.cs)
 
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-<pre><code  data-sample='assets/sln/Dapper.DAL.Tests/StudentRepositoryTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
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   * **UnitOfWork** design pattern
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs)
 
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+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/UnitOfWork/UnitOfWork.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/UnitOfWork/UnitOfWork.cs)
 
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   * Represents the **actual data and information**
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Mappers/IMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Mappers/IMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/IMapper.cs)
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/AddressDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/AddressDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/DetailModels/AddressDetailModel.cs)
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs)
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Models/ListModels/StudentListModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Models/ListModels/StudentListModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Models/ListModels/StudentListModel.cs)
 
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-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/StudentDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/StudentDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Models/DetailModels/StudentDetailModel.cs)
 
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 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs)
 
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+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Facades/CrudFacadeBase.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Facades/CrudFacadeBase.cs)
 
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 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL.Tests/AddressFacadeTests.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL.Tests/StudentFacadeTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL.Tests/StudentFacadeTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL.Tests/StudentFacadeTests.cs)
 
 </script></section></section><section ><section data-markdown><script type="text/template">
diff --git a/Lectures/Lecture_04/_site/assets/sln/Dapper.DAL.Tests/Dapper.DAL.Tests.csproj b/Lectures/Lecture_04/_site/assets/sln/Dapper.DAL.Tests/Dapper.DAL.Tests.csproj
index 6e86aca3..5191de71 100644
--- a/Lectures/Lecture_04/_site/assets/sln/Dapper.DAL.Tests/Dapper.DAL.Tests.csproj
+++ b/Lectures/Lecture_04/_site/assets/sln/Dapper.DAL.Tests/Dapper.DAL.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Lectures/Lecture_04/_site/assets/sln/Dapper.DAL/Dapper.DAL.csproj b/Lectures/Lecture_04/_site/assets/sln/Dapper.DAL/Dapper.DAL.csproj
index 7f9a774e..ce9637da 100644
--- a/Lectures/Lecture_04/_site/assets/sln/Dapper.DAL/Dapper.DAL.csproj
+++ b/Lectures/Lecture_04/_site/assets/sln/Dapper.DAL/Dapper.DAL.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL.Tests/School.BL.Tests.csproj b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL.Tests/School.BL.Tests.csproj
index 0435ee5c..7f78139b 100644
--- a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL.Tests/School.BL.Tests.csproj
+++ b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL.Tests/School.BL.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
 
     <IsPackable>false</IsPackable>
   </PropertyGroup>
diff --git a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs
index 8655512c..e52b7b9e 100644
--- a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs
+++ b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs
@@ -14,7 +14,7 @@ public IEnumerable<AddressDetailModel> Map(IQueryable<AddressEntity> entities)
             => entities?.Select(entity => Map(entity)).ToValueCollection();
 
         public AddressDetailModel Map(AddressEntity entity) 
-            => entity == null? null : new AddressDetailModel
+            => entity is null? null : new AddressDetailModel
             {
                 Id = entity.Id,
                 City = entity.City,
diff --git a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/CourseMapper.cs b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/CourseMapper.cs
index 302bc85e..7088ae9a 100644
--- a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/CourseMapper.cs
+++ b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/CourseMapper.cs
@@ -22,7 +22,7 @@ public IEnumerable<CourseListModel> Map(IQueryable<CourseEntity> entities)
             }).ToValueCollection();
 
         public CourseDetailModel Map(CourseEntity entity) 
-            => entity == null
+            => entity is null
                 ? null
                 : new CourseDetailModel
                 {
diff --git a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/GradeMapper.cs b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/GradeMapper.cs
index 4170cb51..3d3fc2f7 100644
--- a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/GradeMapper.cs
+++ b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/GradeMapper.cs
@@ -23,7 +23,7 @@ public GradeListModel MapListModel(GradeEntity entity) =>
             };
 
         public GradeDetailModel Map(GradeEntity entity) 
-            => entity == null
+            => entity is null
             ? null
             : new GradeDetailModel
             {
diff --git a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs
index ecc808e3..7fd9865f 100644
--- a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs
+++ b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs
@@ -22,7 +22,7 @@ public IEnumerable<StudentListModel> Map(IQueryable<StudentEntity> entities)
             }).ToValueCollection();
         }
 
-        public StudentDetailModel Map(StudentEntity entity) => entity == null
+        public StudentDetailModel Map(StudentEntity entity) => entity is null
             ? null
             : new StudentDetailModel
             {
diff --git a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/School.BL.csproj b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/School.BL.csproj
index 61de9d2e..171643be 100644
--- a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/School.BL.csproj
+++ b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.BL/School.BL.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL.Tests/School.DAL.Tests.csproj b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL.Tests/School.DAL.Tests.csproj
index aa655fad..71ed5392 100644
--- a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL.Tests/School.DAL.Tests.csproj
+++ b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL.Tests/School.DAL.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <StartupObject />
   </PropertyGroup>
 
diff --git a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/Factories/EntityFactory.cs b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/Factories/EntityFactory.cs
index b8a9b4d6..24af8f3a 100644
--- a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/Factories/EntityFactory.cs
+++ b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/Factories/EntityFactory.cs
@@ -20,7 +20,7 @@ public class EntityFactory : IEntityFactory
                     .Entries<TEntity>()
                     .SingleOrDefault(i => i.Entity.Id == id)
                     ?.Entity;
-                if (entity == null)
+                if (entity is null)
                 {
                     entity = new TEntity { Id = id };
                     _changeTracker?.Context.Attach(entity);
diff --git a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs
index 5b625ab2..c4343c92 100644
--- a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs
+++ b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs
@@ -67,7 +67,7 @@ private void SynchronizeCollections(TEntity entity)
         }
 
         var entityInDb = GetById(entity.Id);
-        if (entityInDb == null) return;
+        if (entityInDb is null) return;
 
         foreach (var collectionSelector in toBeSynchronized)
         {
diff --git a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/School.DAL.csproj b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/School.DAL.csproj
index 7c5c3070..4edd43f2 100644
--- a/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/School.DAL.csproj
+++ b/Lectures/Lecture_04/_site/assets/sln/EntityFramework/School.DAL/School.DAL.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
diff --git a/Lectures/Lecture_04/_site/assets/sln/Examples/Examples.csproj b/Lectures/Lecture_04/_site/assets/sln/Examples/Examples.csproj
index d7570976..d4ec8ec6 100644
--- a/Lectures/Lecture_04/_site/assets/sln/Examples/Examples.csproj
+++ b/Lectures/Lecture_04/_site/assets/sln/Examples/Examples.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Lectures/Lecture_04/_site/index.html b/Lectures/Lecture_04/_site/index.html
index 3fc3f8ce..d5997d64 100644
--- a/Lectures/Lecture_04/_site/index.html
+++ b/Lectures/Lecture_04/_site/index.html
@@ -275,7 +275,7 @@
 
 </script></section><section data-markdown><script type="text/template">
 
-<pre><code  data-sample='assets/sln/Examples/SqlClientExample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Examples/SqlClientExample.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- +++?code=assets/sln/Examples/SqlClientExample.cs&lang=C#&title=ADO.NET SqlClient Sample
 @[10-53]
 @[10-12]
@@ -505,7 +505,7 @@
         * Represents multiplicity of many (*)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
@@ -543,7 +543,7 @@
   5. Each collection **property** must be `ICollection<T>`
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityTypesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityTypesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 <!-- +++?code=assets/sln/EntityFramework/School.DAL.Tests/EntityTypesTest.cs&lang=C#&title=Entity Types Sample
 @[13-21]
@@ -572,7 +572,7 @@
 * Other changes must be made **explicitly using** proper **methods of **`DbContext`** or **`DbSet`
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityStatesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL.Tests/EntityStatesTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 <!-- +++?code=assets/sln/EntityFramework/School.DAL.Tests/EntityStatesTest.cs&lang=C#&title=Entity States Sample
 @[12-24]
@@ -666,16 +666,16 @@
 ```
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Dapper.DAL/appconfig.json' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Dapper.DAL/appconfig.json' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/appconfig.json)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/SchoolDbContext.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/SchoolDbContext.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[9-30] -->
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/SchoolDbContext.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL.Tests/LinqLazyEvaluationTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL.Tests/LinqLazyEvaluationTest.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[13-21]
 @[23-34] -->
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL.Tests/LinqLazyEvaluationTest.cs)
@@ -1047,11 +1047,11 @@
 ```
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/AddressEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/AddressEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/AddressEntity.cs)
 
 </script></section><section data-markdown><script type="text/template">
@@ -1122,11 +1122,11 @@
 ```
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/GradeEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/GradeEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/GradeEntity.cs)
 
 </script></section><section data-markdown><script type="text/template">
@@ -1153,15 +1153,15 @@
 ```
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentEntity.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/CourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/CourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/CourseEntity.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentCourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Entities/StudentCourseEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Entities/StudentCourseEntity.cs)
 
 
@@ -1224,11 +1224,11 @@
   3. *Pass query as a parameter in Execute method*
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Dapper.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Dapper.DAL/Entities/StudentEntity.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/Dapper.DAL/Entities/StudentEntity.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Dapper.DAL/StudentRepository.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Dapper.DAL/StudentRepository.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[20-30]
 @[32-42]
 @[44-53]
@@ -1236,7 +1236,7 @@
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/Dapper.DAL/StudentRepository.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/Dapper.DAL.Tests/StudentRepositoryTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/Dapper.DAL.Tests/StudentRepositoryTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 <!-- @[12-28] -->
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/Dapper.DAL.Tests/StudentRepositoryTests.cs)
 
@@ -1535,7 +1535,7 @@
   * **UnitOfWork** design pattern
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs)
 
 </script></section></section><section ><section data-markdown><script type="text/template">
@@ -1546,7 +1546,7 @@
 ![](assets/img/UnitOfWork.jpg)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.DAL/UnitOfWork/UnitOfWork.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.DAL/UnitOfWork/UnitOfWork.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/UnitOfWork/UnitOfWork.cs)
 
 </script></section></section><section ><section data-markdown><script type="text/template">
@@ -1602,27 +1602,27 @@
   * Represents the **actual data and information**
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Mappers/IMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Mappers/IMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/IMapper.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/AddressDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/AddressDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/DetailModels/AddressDetailModel.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Models/ListModels/StudentListModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Models/ListModels/StudentListModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Models/ListModels/StudentListModel.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/StudentDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Models/DetailModels/StudentDetailModel.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Models/DetailModels/StudentDetailModel.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs)
 
 </script></section></section><section ><section data-markdown><script type="text/template">
@@ -1729,17 +1729,17 @@
   * Have no knowledge of the facade and keep no reference to it
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL/Facades/CrudFacadeBase.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL/Facades/CrudFacadeBase.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 
 
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Facades/CrudFacadeBase.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL.Tests/AddressFacadeTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL.Tests/AddressFacadeTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL.Tests/AddressFacadeTests.cs)
 
 </script></section><section data-markdown><script type="text/template">
-<pre><code  data-sample='assets/sln/EntityFramework/School.BL.Tests/StudentFacadeTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
+<pre><code class="language-csharp" data-sample='assets/sln/EntityFramework/School.BL.Tests/StudentFacadeTests.cs' data-sample-line-numbers="true" data-sample-indent="remove"></code></pre>
 [Code sample](https://github.com/nesfit/ICS/blob/master/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL.Tests/StudentFacadeTests.cs)
 
 </script></section></section><section ><section data-markdown><script type="text/template">
diff --git a/Lectures/Lecture_04/assets/sln/Dapper.DAL.Tests/Dapper.DAL.Tests.csproj b/Lectures/Lecture_04/assets/sln/Dapper.DAL.Tests/Dapper.DAL.Tests.csproj
index 6e86aca3..5191de71 100644
--- a/Lectures/Lecture_04/assets/sln/Dapper.DAL.Tests/Dapper.DAL.Tests.csproj
+++ b/Lectures/Lecture_04/assets/sln/Dapper.DAL.Tests/Dapper.DAL.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Lectures/Lecture_04/assets/sln/Dapper.DAL/Dapper.DAL.csproj b/Lectures/Lecture_04/assets/sln/Dapper.DAL/Dapper.DAL.csproj
index 7f9a774e..ce9637da 100644
--- a/Lectures/Lecture_04/assets/sln/Dapper.DAL/Dapper.DAL.csproj
+++ b/Lectures/Lecture_04/assets/sln/Dapper.DAL/Dapper.DAL.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL.Tests/School.BL.Tests.csproj b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL.Tests/School.BL.Tests.csproj
index 0435ee5c..7f78139b 100644
--- a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL.Tests/School.BL.Tests.csproj
+++ b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL.Tests/School.BL.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
 
     <IsPackable>false</IsPackable>
   </PropertyGroup>
diff --git a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs
index 8655512c..e52b7b9e 100644
--- a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs
+++ b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/AddressMapper.cs
@@ -14,7 +14,7 @@ public IEnumerable<AddressDetailModel> Map(IQueryable<AddressEntity> entities)
             => entities?.Select(entity => Map(entity)).ToValueCollection();
 
         public AddressDetailModel Map(AddressEntity entity) 
-            => entity == null? null : new AddressDetailModel
+            => entity is null? null : new AddressDetailModel
             {
                 Id = entity.Id,
                 City = entity.City,
diff --git a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/CourseMapper.cs b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/CourseMapper.cs
index 302bc85e..7088ae9a 100644
--- a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/CourseMapper.cs
+++ b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/CourseMapper.cs
@@ -22,7 +22,7 @@ public IEnumerable<CourseListModel> Map(IQueryable<CourseEntity> entities)
             }).ToValueCollection();
 
         public CourseDetailModel Map(CourseEntity entity) 
-            => entity == null
+            => entity is null
                 ? null
                 : new CourseDetailModel
                 {
diff --git a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/GradeMapper.cs b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/GradeMapper.cs
index 4170cb51..3d3fc2f7 100644
--- a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/GradeMapper.cs
+++ b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/GradeMapper.cs
@@ -23,7 +23,7 @@ public GradeListModel MapListModel(GradeEntity entity) =>
             };
 
         public GradeDetailModel Map(GradeEntity entity) 
-            => entity == null
+            => entity is null
             ? null
             : new GradeDetailModel
             {
diff --git a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs
index ecc808e3..7fd9865f 100644
--- a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs
+++ b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/Mappers/StudentMapper.cs
@@ -22,7 +22,7 @@ public IEnumerable<StudentListModel> Map(IQueryable<StudentEntity> entities)
             }).ToValueCollection();
         }
 
-        public StudentDetailModel Map(StudentEntity entity) => entity == null
+        public StudentDetailModel Map(StudentEntity entity) => entity is null
             ? null
             : new StudentDetailModel
             {
diff --git a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/School.BL.csproj b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/School.BL.csproj
index 61de9d2e..171643be 100644
--- a/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/School.BL.csproj
+++ b/Lectures/Lecture_04/assets/sln/EntityFramework/School.BL/School.BL.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL.Tests/School.DAL.Tests.csproj b/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL.Tests/School.DAL.Tests.csproj
index aa655fad..71ed5392 100644
--- a/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL.Tests/School.DAL.Tests.csproj
+++ b/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL.Tests/School.DAL.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <StartupObject />
   </PropertyGroup>
 
diff --git a/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Factories/EntityFactory.cs b/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Factories/EntityFactory.cs
index b8a9b4d6..24af8f3a 100644
--- a/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Factories/EntityFactory.cs
+++ b/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Factories/EntityFactory.cs
@@ -20,7 +20,7 @@ public class EntityFactory : IEntityFactory
                     .Entries<TEntity>()
                     .SingleOrDefault(i => i.Entity.Id == id)
                     ?.Entity;
-                if (entity == null)
+                if (entity is null)
                 {
                     entity = new TEntity { Id = id };
                     _changeTracker?.Context.Attach(entity);
diff --git a/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs b/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs
index 5b625ab2..c4343c92 100644
--- a/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs
+++ b/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/Repositories/RepositoryBase.cs
@@ -67,7 +67,7 @@ private void SynchronizeCollections(TEntity entity)
         }
 
         var entityInDb = GetById(entity.Id);
-        if (entityInDb == null) return;
+        if (entityInDb is null) return;
 
         foreach (var collectionSelector in toBeSynchronized)
         {
diff --git a/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/School.DAL.csproj b/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/School.DAL.csproj
index 7c5c3070..4edd43f2 100644
--- a/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/School.DAL.csproj
+++ b/Lectures/Lecture_04/assets/sln/EntityFramework/School.DAL/School.DAL.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
diff --git a/Lectures/Lecture_04/assets/sln/Examples/Examples.csproj b/Lectures/Lecture_04/assets/sln/Examples/Examples.csproj
index d7570976..d4ec8ec6 100644
--- a/Lectures/Lecture_04/assets/sln/Examples/Examples.csproj
+++ b/Lectures/Lecture_04/assets/sln/Examples/Examples.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Converters/NullToVisibilityConverter.cs b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Converters/NullToVisibilityConverter.cs
index 460ad9e8..b8bc694e 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Converters/NullToVisibilityConverter.cs
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Converters/NullToVisibilityConverter.cs
@@ -13,7 +13,7 @@ public class NullToVisibilityConverter : IValueConverter
     {
         public object Convert(object? value, Type targetType, object parameter, CultureInfo culture)
         {
-            return value == null ? Visibility.Collapsed : Visibility.Visible;
+            return value is null ? Visibility.Collapsed : Visibility.Visible;
         }
 
         public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/CookBook.App.csproj b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/CookBook.App.csproj
index 262f1ee5..17d629ea 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/CookBook.App.csproj
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/CookBook.App.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
-    <TargetFramework>net6.0-windows</TargetFramework>
+    <TargetFramework>net8.0-windows</TargetFramework>
     <nullable>enable</nullable>
     <UseWPF>true</UseWPF>
   </PropertyGroup>
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/IngredientAmountDetailViewModel.cs b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/IngredientAmountDetailViewModel.cs
index 7d30ce29..6e256988 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/IngredientAmountDetailViewModel.cs
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/IngredientAmountDetailViewModel.cs
@@ -87,7 +87,7 @@ private void Delete()
 
         private void Save()
         {
-            if (Model == null)
+            if (Model is null)
             {
                 throw new InvalidOperationException("Null model cannot be saved");
             }
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/IngredientDetailViewModel.cs b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/IngredientDetailViewModel.cs
index 61e85807..e6b1cb0e 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/IngredientDetailViewModel.cs
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/IngredientDetailViewModel.cs
@@ -42,7 +42,7 @@ public async Task LoadAsync(Guid id)
 
         public async Task SaveAsync()
         {
-            if (Model == null)
+            if (Model is null)
             {
                 throw new InvalidOperationException("Null model cannot be saved");
             }
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/MainViewModel.cs b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/MainViewModel.cs
index 64e0702a..d0f91c0f 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/MainViewModel.cs
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/MainViewModel.cs
@@ -114,7 +114,7 @@ private void SelectRecipe(Guid? id)
             else
             {
                 var recipeDetailViewModel = RecipeDetailViewModels.SingleOrDefault(vm => vm.Model?.Id == id);
-                if (recipeDetailViewModel == null)
+                if (recipeDetailViewModel is null)
                 {
                     recipeDetailViewModel = _recipeDetailViewModelFactory.Create();
                     RecipeDetailViewModels.Add(recipeDetailViewModel);
@@ -135,7 +135,7 @@ private void SelectIngredient(Guid? id)
             {
                 var ingredientDetailViewModel =
                     IngredientDetailViewModels.SingleOrDefault(vm => vm.Model?.Id == id);
-                if (ingredientDetailViewModel == null)
+                if (ingredientDetailViewModel is null)
                 {
                     ingredientDetailViewModel = _ingredientDetailViewModelFactory.Create();
                     IngredientDetailViewModels.Add(ingredientDetailViewModel);
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/RecipeDetailViewModel.cs b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/RecipeDetailViewModel.cs
index 3c458790..fbe0e9c6 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/RecipeDetailViewModel.cs
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/ViewModels/RecipeDetailViewModel.cs
@@ -144,7 +144,7 @@ public async Task DeleteAsync()
 
         public async Task SaveAsync()
         {
-            if (Model == null)
+            if (Model is null)
             {
                 throw new InvalidOperationException("Null model cannot be saved");
             }
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Wrappers/ModelWrapper.cs b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Wrappers/ModelWrapper.cs
index b7d9570c..f135b0ce 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Wrappers/ModelWrapper.cs
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Wrappers/ModelWrapper.cs
@@ -19,7 +19,7 @@ public abstract class ModelWrapper<T> : ViewModelBase, IModel, IValidatableObjec
     {
         protected ModelWrapper(T? model)
         {
-            if (model == null)
+            if (model is null)
             {
                 throw new ArgumentNullException(nameof(model));
             }
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Wrappers/RecipeWrapper.cs b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Wrappers/RecipeWrapper.cs
index b3676c1c..43be483f 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Wrappers/RecipeWrapper.cs
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.App/Wrappers/RecipeWrapper.cs
@@ -46,7 +46,7 @@ public string? ImageUrl
 
         private void InitializeCollectionProperties(RecipeDetailModel model)
         {
-            if (model.Ingredients == null)
+            if (model.Ingredients is null)
             {
                 throw new ArgumentException("Ingredients cannot be null");
             }
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.BL.Tests/CookBook.BL.Tests.csproj b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.BL.Tests/CookBook.BL.Tests.csproj
index 3bdf51cd..5e46d537 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.BL.Tests/CookBook.BL.Tests.csproj
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.BL.Tests/CookBook.BL.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <nullable>annotations</nullable>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.BL/CookBook.BL.csproj b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.BL/CookBook.BL.csproj
index c2e74c21..f6a3621d 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.BL/CookBook.BL.csproj
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.BL/CookBook.BL.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.Common.Tests/CookBook.Common.Tests.csproj b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.Common.Tests/CookBook.Common.Tests.csproj
index 48bbc1e3..23f67ddb 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.Common.Tests/CookBook.Common.Tests.csproj
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.Common.Tests/CookBook.Common.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.Common/CookBook.Common.csproj b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.Common/CookBook.Common.csproj
index dbc15171..58990cd5 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.Common/CookBook.Common.csproj
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.Common/CookBook.Common.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
 </Project>
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL.Tests/CookBook.DAL.Tests.csproj b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL.Tests/CookBook.DAL.Tests.csproj
index 64849349..b93704dd 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL.Tests/CookBook.DAL.Tests.csproj
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL.Tests/CookBook.DAL.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
 
     <Nullable>enable</Nullable>
     <IsPackable>false</IsPackable>
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL/CookBook.DAL.csproj b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL/CookBook.DAL.csproj
index 021b6e68..055023ab 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL/CookBook.DAL.csproj
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL/CookBook.DAL.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
diff --git a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL/UnitOfWork/QueryableExtensions.cs b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL/UnitOfWork/QueryableExtensions.cs
index 45e832a2..7f744980 100644
--- a/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL/UnitOfWork/QueryableExtensions.cs
+++ b/Lectures/Lecture_06/CookBookCI/CookBook/CookBook.DAL/UnitOfWork/QueryableExtensions.cs
@@ -20,7 +20,7 @@ public static async Task PreLoadChangeTracker<TEntity>(this IQueryable<TEntity>
     public static IQueryable<TEntity> IncludeFirstLevelNavigationProperties<TEntity>(this IQueryable<TEntity> query, Microsoft.EntityFrameworkCore.Metadata.IModel model) where TEntity : class
     {
         var navigationProperties = model.FindEntityType(typeof(TEntity))?.GetNavigations();
-        if (navigationProperties == null)
+        if (navigationProperties is null)
             return query;
 
         foreach (var navigationProperty in navigationProperties)
diff --git a/Lectures/Lecture_10/Lecture.md b/Lectures/Lecture_10/Lecture.md
index 2e6bcf2d..04c52e75 100644
--- a/Lectures/Lecture_10/Lecture.md
+++ b/Lectures/Lecture_10/Lecture.md
@@ -1,16 +1,10 @@
 ---
 title: ICS 10 - Multiplatform Development and Application Containerization
-theme: simple
 css: _reveal-md/theme.css
+theme: simple
 separator: "^---$"
 verticalSeparator: "^\\+\\+\\+$"
-highlightTheme: vs
-progress: true
-slideNumber: true
-mouseWheel: false
-enableMenu: true
-enableChalkboard: true
-enableTitleFooter: true
+highlightTheme: "vs"
 ---
 
 # Multiplatform Development and Application Containerization
diff --git a/Lectures/Lecture_11/Lecture.md b/Lectures/Lecture_11/Lecture.md
index 36a28a1f..b91f1081 100644
--- a/Lectures/Lecture_11/Lecture.md
+++ b/Lectures/Lecture_11/Lecture.md
@@ -1,16 +1,10 @@
 ---
 title: ICS 11 - Parallel programming
-theme: simple
 css: _reveal-md/theme.css
+theme: simple
 separator: "^---$"
 verticalSeparator: "^\\+\\+\\+$"
-highlightTheme: vs
-progress: true
-slideNumber: true
-mouseWheel: false
-enableMenu: true
-enableChalkboard: true
-enableTitleFooter: true
+highlightTheme: "vs"
 ---
 
 # Parallel programming
diff --git a/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/AsynchronousProgramming.Samples.csproj b/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/AsynchronousProgramming.Samples.csproj
index 4a13ddfe..a729b1ce 100644
--- a/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/AsynchronousProgramming.Samples.csproj
+++ b/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/AsynchronousProgramming.Samples.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
-    <TargetFramework>net6.0-windows</TargetFramework>
+    <TargetFramework>net8.0-windows</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <UseWPF>true</UseWPF>
   </PropertyGroup>
diff --git a/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/Properties/Annotations.cs b/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/Properties/Annotations.cs
index d27c4a02..2528ddde 100644
--- a/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/Properties/Annotations.cs
+++ b/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/Properties/Annotations.cs
@@ -180,7 +180,7 @@ public ValueProviderAttribute([NotNull] string name)
   /// </summary>
   /// <example><code>
   /// void Foo(string param) {
-  ///   if (param == null)
+  ///   if (param is null)
   ///     throw new ArgumentNullException("par"); // Warning: Cannot resolve symbol
   /// }
   /// </code></example>
diff --git a/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/Properties/Resources.Designer.cs b/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/Properties/Resources.Designer.cs
index b4b43289..36425d27 100644
--- a/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/Properties/Resources.Designer.cs
+++ b/Lectures/Lecture_11/_site/assets/sln/AsynchronousProgramming.Samples/Properties/Resources.Designer.cs
@@ -42,7 +42,7 @@ internal Resources()
         {
             get
             {
-                if ((resourceMan == null))
+                if ((resourceMan is null))
                 {
                     global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("AsynchronousProgramming.Samples.Properties.Resources", typeof(Resources).Assembly);
                     resourceMan = temp;
diff --git a/Lectures/Lecture_11/_site/assets/sln/ParallelProgramming.Sampels/ParallelProgramming.Samples.csproj b/Lectures/Lecture_11/_site/assets/sln/ParallelProgramming.Sampels/ParallelProgramming.Samples.csproj
index 3e1b9dc9..24cefb27 100644
--- a/Lectures/Lecture_11/_site/assets/sln/ParallelProgramming.Sampels/ParallelProgramming.Samples.csproj
+++ b/Lectures/Lecture_11/_site/assets/sln/ParallelProgramming.Sampels/ParallelProgramming.Samples.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>net6.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
 
         <IsPackable>false</IsPackable>
 
diff --git a/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/AsynchronousProgramming.Samples.csproj b/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/AsynchronousProgramming.Samples.csproj
index 4a13ddfe..a729b1ce 100644
--- a/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/AsynchronousProgramming.Samples.csproj
+++ b/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/AsynchronousProgramming.Samples.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
-    <TargetFramework>net6.0-windows</TargetFramework>
+    <TargetFramework>net8.0-windows</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <UseWPF>true</UseWPF>
   </PropertyGroup>
diff --git a/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/Properties/Annotations.cs b/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/Properties/Annotations.cs
index d27c4a02..2528ddde 100644
--- a/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/Properties/Annotations.cs
+++ b/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/Properties/Annotations.cs
@@ -180,7 +180,7 @@ public ValueProviderAttribute([NotNull] string name)
   /// </summary>
   /// <example><code>
   /// void Foo(string param) {
-  ///   if (param == null)
+  ///   if (param is null)
   ///     throw new ArgumentNullException("par"); // Warning: Cannot resolve symbol
   /// }
   /// </code></example>
diff --git a/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/Properties/Resources.Designer.cs b/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/Properties/Resources.Designer.cs
index b4b43289..36425d27 100644
--- a/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/Properties/Resources.Designer.cs
+++ b/Lectures/Lecture_11/assets/sln/AsynchronousProgramming.Samples/Properties/Resources.Designer.cs
@@ -42,7 +42,7 @@ internal Resources()
         {
             get
             {
-                if ((resourceMan == null))
+                if ((resourceMan is null))
                 {
                     global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("AsynchronousProgramming.Samples.Properties.Resources", typeof(Resources).Assembly);
                     resourceMan = temp;
diff --git a/Lectures/Lecture_11/assets/sln/ParallelProgramming.Sampels/ParallelProgramming.Samples.csproj b/Lectures/Lecture_11/assets/sln/ParallelProgramming.Sampels/ParallelProgramming.Samples.csproj
index 3e1b9dc9..24cefb27 100644
--- a/Lectures/Lecture_11/assets/sln/ParallelProgramming.Sampels/ParallelProgramming.Samples.csproj
+++ b/Lectures/Lecture_11/assets/sln/ParallelProgramming.Sampels/ParallelProgramming.Samples.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>net6.0</TargetFramework>
+        <TargetFramework>net8.0</TargetFramework>
 
         <IsPackable>false</IsPackable>
 
diff --git a/Lectures/_reveal-md/reveal.json b/Lectures/_reveal-md/reveal.json
index 6bcd1348..5bbf48f8 100644
--- a/Lectures/_reveal-md/reveal.json
+++ b/Lectures/_reveal-md/reveal.json
@@ -3,7 +3,6 @@
     "controlsTutorial": true,
     "controlsLayout": "bottom-right",
     "progress": true,
-    "slideNumber": true,
     "showSlideNumber": "all",
     "keyboard": true,
     "overview": true,
@@ -13,5 +12,9 @@
     "help": true,
     "mouseWheel": false,
     "transition": "slide",
-    "transitionSpeed": "fast"
+    "transitionSpeed": "fast",
+    "slideNumber": "c/t",
+    "enableMenu": true,
+    "enableChalkboard": true,
+    "enableTitleFooter": true
 }
diff --git a/README.md b/README.md
index 81e5b0ce..9e7a9ab3 100644
--- a/README.md
+++ b/README.md
@@ -44,36 +44,39 @@ Cvičení jsou demonstrační. Pokud možno, přineste si vlastní zařízení,
 
 ## Plán semestru
 
-| Datum  | Typ | Vyučující       | Téma přednášky                                                                                                                                                                                                                                                                               |
-| ------ | --- | --------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| 8.02.  | L01 | Jan Pluskal     | [Úvod do jazyka C# a platformy .NET](https://nesfit.github.io/ICS/Lectures/Lecture_01/_site/) - základní syntaxe jazyka ([verze pro tisk](https://nesfit.github.io/ICS/Lectures/Lecture_01/_site/?print-pdf))                                                                                |
-|        | E01 | Jan Pluskal     | Práce s Visual Studio 2022, debugování a Azure DevOps založení projektu (základy pro zracování projektu)                                                                                                                                                                                     |
-| 15.02. | L02 | Jan Pluskal     | [Úvod do Objektově Orientovaného Programování](https://nesfit.github.io/ICS/Lectures/Lecture_02/_site/) ([verze pro tisk](https://nesfit.github.io/ICS/Lectures/Lecture_02/_site/?print-pdf))                                                                                                |
-|        | E02 | Jan Pluskal     | Objektově orientované programování a úvod do Entity Framework                                                                                                                                                                                                                                |
-| 22.02. | L03 | Tibor Jašek     | [Představení základních knihovních funkcí (BCL)](https://nesfit.github.io/ICS/Lectures/Lecture_03/_site/) - dotazování za pomocí vestavěného nástroje LINQ nad datovými zdroji (kolekcemi, XML, MSSQL) ([verze pro tisk](https://nesfit.github.io/ICS/Lectures/Lecture_03/_site/?print-pdf)) |
-| 29.02. | L04 | Jan Pluskal     | [Propojení aplikace s databází](https://nesfit.github.io/ICS/Lectures/Lecture_04/_site/) ([verze pro tisk](https://nesfit.github.io/ICS/Lectures/Lecture_04/_site/?print-pdf))                                                                                                               |
-|        | E03 | Jan Pluskal     | Entity framework                                                                                                                                                                                                                                                                             |
-| 03.03. | P01 |                 | **Odevzdání první fáze projektu**                                                                                                                                                                                                                                                            |
-| 07.03. | L05 | Martin Dybal    | Psaní čistého a udržovatelného kódu                                                                                                                                                                                                                                                          |
-| 14.03. | L06 | Michal Tichý    | Automatizované testování - práce s xUnit, CI                                                                                                                                                                                                                                                 |
-| 21.03. | L07 | Michal Mrnuštík | Návrhový vzor Model-View-ViewModel                                                                                                                                                                                                                                                           |
+| Datum  | Typ | Vyučující   | Téma přednášky                                                                                                                                                                                                                                                                               |
+| ------ | --- | ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| 8.02.  | L01 | Jan Pluskal | [Úvod do jazyka C# a platformy .NET](https://nesfit.github.io/ICS/Lectures/Lecture_01/_site/) - základní syntaxe jazyka ([verze pro tisk](https://nesfit.github.io/ICS/Lectures/Lecture_01/_site/?print-pdf))                                                                                |
+|        | E01 | Jan Pluskal | Práce s Visual Studio 2022, debugování a Azure DevOps založení projektu (základy pro zracování projektu)                                                                                                                                                                                     |
+| 15.02. | L02 | Jan Pluskal | [Úvod do Objektově Orientovaného Programování](https://nesfit.github.io/ICS/Lectures/Lecture_02/_site/) ([verze pro tisk](https://nesfit.github.io/ICS/Lectures/Lecture_02/_site/?print-pdf))                                                                                                |
+|        | E02 | Jan Pluskal | Objektově orientované programování a úvod do Entity Framework                                                                                                                                                                                                                                |
+| 22.02. | L03 | Tibor Jašek | [Představení základních knihovních funkcí (BCL)](https://nesfit.github.io/ICS/Lectures/Lecture_03/_site/) - dotazování za pomocí vestavěného nástroje LINQ nad datovými zdroji (kolekcemi, XML, MSSQL) ([verze pro tisk](https://nesfit.github.io/ICS/Lectures/Lecture_03/_site/?print-pdf)) |
+| 29.02. | L04 | Jan Pluskal | [Propojení aplikace s databází](https://nesfit.github.io/ICS/Lectures/Lecture_04/_site/) ([verze pro tisk](https://nesfit.github.io/ICS/Lectures/Lecture_04/_site/?print-pdf))                                                                                                               |
+|        | E03 | Jan Pluskal | Entity framework                                                                                                                                                                                                                                                                             |
+| 03.03. | P01 |             | **Odevzdání první fáze projektu**                                                                                                                                                                                                                                                            |
++++
+
+| Datum  | Typ | Vyučující       | Téma přednášky                               |
+| ------ | --- | --------------- | -------------------------------------------- |
+| 07.03. | L05 | Martin Dybal    | Psaní čistého a udržovatelného kódu          |
+| 14.03. | L06 | Michal Tichý    | Automatizované testování - práce s xUnit, CI |
+| 21.03. | L07 | Michal Mrnuštík | Návrhový vzor Model-View-ViewModel           |
+| 28.03. | L08 | Roman Jašek     | MAUI                                         |
+|        | E04 | Roman Jašek     | MAUI                                         |
+| 04.04. | L09 | Roman Jašek     | MAUI                                         |
+|        | E05 | Roman Jašek     | MAUI                                         |
+| 07.04. | P02 |                 | **Odevzdání druhé fáze projektu**            |
 
 +++
 
 | Datum  | Typ | Vyučující    | Téma přednášky                                                                                                                                                                                                                                        |
 | ------ | --- | ------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-|        |
-| 28.03. | L08 | Roman Jašek  | MAUI                                                                                                                                                                                                                                                  |
-|        | E04 | Roman Jašek  | MAUI                                                                                                                                                                                                                                                  |
-| 04.04. | L09 | Roman Jašek  | MAUI                                                                                                                                                                                                                                                  |
-|        | E05 | Roman Jašek  | MAUI                                                                                                                                                                                                                                                  |
-| 07.04. | P02 |              | **Odevzdání druhé fáze projektu**                                                                                                                                                                                                                     |
 | 11.04. | L10 | Jan Pluskal  | [Multiplatformní programování](https://nesfit.github.io/ICS/Lectures/Lecture_10/_site/) - .NET Standard, .NET Core., .NET, kontejnerizace a deployment aplikací ([verze pro tisk](https://nesfit.github.io/ICS/Lectures/Lecture_10/_site/?print-pdf)) |
 | 18.04. | L11 | Jan Pluskal  | [Paralelní a asynchronní programování](https://nesfit.github.io/ICS/Lectures/Lecture_11/_site/) - proces, vlákno, úloha z pohledu C# a použitého .NET frameworku                                                                                      |
 |        | E06 | Jan Pluskal  | Takto můžete napsat projekt?!                                                                                                                                                                                                                         |
 | 25.04. | L12 | Martin Dybal | Návrhové vzory - vytvářecí, strukturní a chování - Gang of Four (GoF) v kontextu C#                                                                                                                                                                   |
-| Dle IS | P03 |              | **Obhajoby projektu**                                                                                                                                                                                                                                 |
 | 02.05. | L13 | Roman Jašek  | Napojení aplikace na API server                                                                                                                                                                                                                       |
+| Dle IS | P03 |              | **Obhajoby projektu**                                                                                                                                                                                                                                 |
 
 LXY - přednáška | EXY - democvičení | P0X - projekt
 
@@ -116,9 +119,10 @@ LXY - přednáška | EXY - democvičení | P0X - projekt
 +++
 
 ```pwsh
-winget install Microsoft.VisualStudio.2022.Community --override "--add Microsoft.VisualStudio.Workload.NetCrossPlat --add Microsoft.VisualStudio.Workload.Data --add Microsoft.VisualStudio.Workload.ManagedDesktop"
-winget install Microsoft.DotNet.SDK.6
-winget install Microsoft.DotNet.SDK.7
+winget install Microsoft.DotNet.SDK.8
+
+winget install Microsoft.VisualStudio.2022.Community --override "--add Microsoft.VisualStudio.Workload.NetCrossPlat --add Microsoft.VisualStudio.Workload.Data --add Microsoft.VisualStudio.Workload.ManagedDesktop Microsoft.VisualStudio.ComponentGroup.WindowsAppSDK.Cs"
+
 winget install JetBrains.ReSharper
 ```
 
@@ -142,6 +146,9 @@ winget install JetBrains.ReSharper
 * [Jan Pluskal](https://www.fit.vut.cz/person/ipluskal)
 * [Michal Koutenský](https://www.fit.vut.cz/person/koutenmi)
 * [Daniel Dolejška](https://www.fit.vut.cz/person/dolejska)
+* [Jan Zavřel](https://www.fit.vut.cz/person/izavrel)
+* [Miroslav Šafář](https://www.linkedin.com/in/miroslav-safar/)
+* [Matěj Mudra](https://www.linkedin.com/in/matěj-mudra-a874461a9/)
 
 ---
 
@@ -170,12 +177,16 @@ aneb co sledovat, pokud se chcete dozvědět víc
 
 * [IW5](https://github.com/nesfit/iw5) - předmět, který navazuje na ICS a pokračuje v tématu vývoje v .NET dál se zaměřením na client-server a webový vývoj
 
++++
+
 ## Co se děje v .NET a co se chystá
 * [.NET Conf](https://www.dotnetconf.net/) - konference, kde se představuje nová verze .NET (jednou ročně - **listopad**)
 * [Microsoft Build](https://build.microsoft.com/en-US/home) - největší konference pro vývojáře od Microsoftu, hromada novinek (jednou ročně - **květen**)
 * [.NET Blog](https://devblogs.microsoft.com/dotnet/) - blog s high-level zprávami o aktuálních novinkách (cca 10-15 článků za měsíc)
 * [Themes of .NET](https://aka.ms/dotnet-product-roadmap) - .NET roadmap - podrobný přehled toho, na čem se pracuje a kdy se to plánuje
 
++++
+
 ## Blogy
 * [Leomaris Reyes](https://askxammy.com/author/leoreyes/) - Blog zaměřený na .NET MAUI
 * [Scott Hanselman](https://www.hanselman.com/blog/) - Různorodá témata, většinou zaměrená na Microsoft technologie. Autor je zkušený speaker z řad Microsoftu.
@@ -183,6 +194,8 @@ aneb co sledovat, pokud se chcete dozvědět víc
 * [Jiří Činčura](https://www.tabsoverspaces.com/) - performance, Entity Framework, databázy, novinky v .NET...
 * [Robert Haken](https://knowledge-base.havit.cz/) - Blazor, webový vývoj, performance
 
++++
+
 ## Twitter
 * @davidfowl - **David Fowler**, jeden z hlavních lidí ve vývoji .NET a ASP .NET
 * @DamianEdwards - **Damian Edwards**, jeden z hlavních lidí ve vývoji .NET a ASP .NET
@@ -194,12 +207,16 @@ aneb co sledovat, pokud se chcete dozvědět víc
 * @troyhunt - **Troy Hunt**, záměr na bezpečnost, autor projektu https://haveibeenpwned.com
 * @dotnetmeme - memes ze světa .NET (ne od Microsoftu)
 
++++
+
 ## Youtube
 * [Nick Chapsas](https://www.youtube.com/@nickchapsas) - novinky v .NET, performance, webový vývoj
 * [James Montemagno](https://www.youtube.com/@JamesMontemagno) - novinky v .NET, .NET MAUI
 * [Gerald Versluis](https://www.youtube.com/@jfversluis) - .NET MAUI
 * [.NET Community Standups](https://www.youtube.com/playlist?list=PLdo4fOcmZ0oX-DBuRG4u58ZTAJgBAeQ-t) - veřejně dostupné streamy z meetingů mezi vývojářema v Microsoftu ohledně toho, co se aktuálně děje a na čem se pracuje
 
++++
+
 ## Podcasty
 * [.NET Rocks](https://www.dotnetrocks.com/) - 2 hodně zkušení hostitelé - Richard Campbell a Carl Fralkin, 1 host, různá témata (hlavně) z .NET světa
 * [The .NET MAUI Podcast](https://www.dotnetmauipodcast.com/) - .NET MAUI, James Montemagno, David Ortinau a Matt Soucoup
diff --git a/flake.lock b/flake.lock
index e6096b5d..da2f5776 100644
--- a/flake.lock
+++ b/flake.lock
@@ -5,11 +5,11 @@
         "systems": "systems"
       },
       "locked": {
-        "lastModified": 1701680307,
-        "narHash": "sha256-kAuep2h5ajznlPMD9rnQyffWG8EM/C73lejGofXvdM8=",
+        "lastModified": 1705309234,
+        "narHash": "sha256-uNRRNRKmJyCRC/8y1RqBkqWBLM034y4qN7EprSdmgyA=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "4022d587cbbfd70fe950c1e2083a02621806a725",
+        "rev": "1ef2e671c3b0c19053962c07dbda38332dcebf26",
         "type": "github"
       },
       "original": {
@@ -20,11 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1704420045,
-        "narHash": "sha256-C36QmoJd5tdQ5R9MC1jM7fBkZW9zBUqbUCsgwS6j4QU=",
+        "lastModified": 1707091808,
+        "narHash": "sha256-LahKBAfGbY836gtpVNnWwBTIzN7yf/uYM/S0g393r0Y=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "c1be43e8e837b8dbee2b3665a007e761680f0c3d",
+        "rev": "9f2ee8c91ac42da3ae6c6a1d21555f283458247e",
         "type": "github"
       },
       "original": {
@@ -36,11 +36,11 @@
     },
     "nixpkgs-unstable": {
       "locked": {
-        "lastModified": 1704538339,
-        "narHash": "sha256-1734d3mQuux9ySvwf6axRWZRBhtcZA9Q8eftD6EZg6U=",
+        "lastModified": 1707092692,
+        "narHash": "sha256-ZbHsm+mGk/izkWtT4xwwqz38fdlwu7nUUKXTOmm4SyE=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "46ae0210ce163b3cba6c7da08840c1d63de9c701",
+        "rev": "faf912b086576fd1a15fca610166c98d47bc667e",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index 8ae2bdf4..2de59b80 100644
--- a/flake.nix
+++ b/flake.nix
@@ -49,6 +49,7 @@
             dotnet-combined
             pkgs.reveal-md
             pkgs.nodePackages.mermaid-cli
+            pkgs.nodejs_21
           ];
           buildInputs = [];
         };
diff --git a/src/CookBook/CookBook.App/CookBook.App.csproj b/src/CookBook/CookBook.App/CookBook.App.csproj
index e87b93ea..f83dffaa 100644
--- a/src/CookBook/CookBook.App/CookBook.App.csproj
+++ b/src/CookBook/CookBook.App/CookBook.App.csproj
@@ -6,7 +6,7 @@
     <OutputType>Exe</OutputType>
     <RootNamespace>CookBook.App</RootNamespace>
     <UseMaui>true</UseMaui>
-    <MauiVersion>8.0.3</MauiVersion>
+    <MauiVersion>8.0.6</MauiVersion>
     <SingleProject>true</SingleProject>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
diff --git a/src/Exercise-01-ConsoleApp/Calculator.Console.App/Calculator.App.csproj b/src/Exercise-01-ConsoleApp/Calculator.Console.App/Calculator.App.csproj
index 697fbfc5..82aee85a 100644
--- a/src/Exercise-01-ConsoleApp/Calculator.Console.App/Calculator.App.csproj
+++ b/src/Exercise-01-ConsoleApp/Calculator.Console.App/Calculator.App.csproj
@@ -2,14 +2,14 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <nullable>enable</nullable>
     <AnalysisLevel>latest</AnalysisLevel>
     <RootNamespace>Calculator.App</RootNamespace>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="CommandLineParser" Version="2.8.0" />
+    <PackageReference Include="CommandLineParser" Version="2.9.1" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/Exercise-01-ConsoleApp/Calculator.Console.App/CalculatorWrapper.cs b/src/Exercise-01-ConsoleApp/Calculator.Console.App/CalculatorWrapper.cs
index 17a89c4c..ac074dd4 100644
--- a/src/Exercise-01-ConsoleApp/Calculator.Console.App/CalculatorWrapper.cs
+++ b/src/Exercise-01-ConsoleApp/Calculator.Console.App/CalculatorWrapper.cs
@@ -21,7 +21,7 @@ internal static void Calculate(CommandLineOptions options)
 
     private static int CheckOperand(int? operand)
     {
-        if (operand == null)
+        if (operand is null)
         {
             throw new ArgumentNullException(nameof(operand), "Operand cannot be null!");
         }
@@ -31,7 +31,7 @@ private static int CheckOperand(int? operand)
 
     private static MathOperation CheckOperation(MathOperation? operation)
     {
-        if (operation == null)
+        if (operation is null)
         {
             throw new ArgumentNullException(nameof(operation), "Operation cannot be null!");
         }
diff --git a/src/Exercise-01-ConsoleApp/Calculator.Utils.Tests/Calculator.Utils.Tests.csproj b/src/Exercise-01-ConsoleApp/Calculator.Utils.Tests/Calculator.Utils.Tests.csproj
index c9a63f06..91636c72 100644
--- a/src/Exercise-01-ConsoleApp/Calculator.Utils.Tests/Calculator.Utils.Tests.csproj
+++ b/src/Exercise-01-ConsoleApp/Calculator.Utils.Tests/Calculator.Utils.Tests.csproj
@@ -1,20 +1,16 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <RootNamespace>Calculator.Utils.Tests</RootNamespace>
 
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
-    <PackageReference Include="xunit" Version="2.4.1" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-      <PrivateAssets>all</PrivateAssets>
-    </PackageReference>
-    <PackageReference Include="coverlet.collector" Version="1.3.0">
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
+    <PackageReference Include="xunit" Version="2.6.6" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
diff --git a/src/Exercise-01-ConsoleApp/Calculator.Utils/Calculator.Utils.csproj b/src/Exercise-01-ConsoleApp/Calculator.Utils/Calculator.Utils.csproj
index 88180040..5f0ea715 100644
--- a/src/Exercise-01-ConsoleApp/Calculator.Utils/Calculator.Utils.csproj
+++ b/src/Exercise-01-ConsoleApp/Calculator.Utils/Calculator.Utils.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <nullable>enable</nullable>
     <AnalysisLevel>latest</AnalysisLevel>
     <RootNamespace>Calculator.Utils</RootNamespace>
diff --git a/src/Exercise-01-ConsoleApp/ConsoleApp/ConsoleApp.csproj b/src/Exercise-01-ConsoleApp/ConsoleApp/ConsoleApp.csproj
index c8483b49..37a0497e 100644
--- a/src/Exercise-01-ConsoleApp/ConsoleApp/ConsoleApp.csproj
+++ b/src/Exercise-01-ConsoleApp/ConsoleApp/ConsoleApp.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <nullable>enable</nullable>
     <AnalysisLevel>latest</AnalysisLevel>
     <RootNamespace>Exercise_01.ConsoleApp</RootNamespace>