diff --git a/DESCRIPTION b/DESCRIPTION
index da2068b5..c236715e 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,8 +1,8 @@
 Package: gDRutils
 Type: Package
 Title: A package with helper functions for processing drug response data
-Version: 1.3.14
-Date: 2024-10-03
+Version: 1.3.15
+Date: 2024-10-07
 Authors@R: c(person("Bartosz", "Czech", role=c("aut"),
                    comment = c(ORCID = "0000-0002-9908-3007")),
              person("Arkadiusz", "Gladki", role=c("cre", "aut"), email="gladki.arkadiusz@gmail.com",
diff --git a/NAMESPACE b/NAMESPACE
index 21026b4d..a9f9de03 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -43,7 +43,9 @@ export(get_SE_identifiers)
 export(get_SE_keys)
 export(get_SE_processing_metadata)
 export(get_additional_variables)
+export(get_assay_dt_duplicated_rows)
 export(get_assay_names)
+export(get_assay_req_uniq_cols)
 export(get_combo_assay_names)
 export(get_combo_base_assay_names)
 export(get_combo_excess_field_names)
@@ -68,6 +70,8 @@ export(get_synthetic_data)
 export(get_testdata)
 export(get_testdata_codilution)
 export(get_testdata_combo)
+export(has_assay_dt_duplicated_rows)
+export(has_dt_duplicated_rows)
 export(has_single_codrug_data)
 export(has_valid_codrug_data)
 export(identify_unique_se_metadata_fields)
@@ -111,6 +115,7 @@ export(shorten_normalization_type_name)
 export(split_SE_components)
 export(standardize_mae)
 export(standardize_se)
+export(throw_msg_if_duplicates)
 export(update_env_idfs_from_mae)
 export(update_idfs_synonyms)
 export(validate_MAE)
diff --git a/NEWS.md b/NEWS.md
index d6c0d80e..149fe90b 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,3 +1,6 @@
+## gDRutils 1.3.15 - 2024-10-07
+* refactor the logic for dealing with duplicates in assay data
+
 ## gDRutils 1.3.14 - 2024-10-03
 * fixed issue in average_biological_replicated (fit_type)
 
diff --git a/R/duplicates.R b/R/duplicates.R
new file mode 100644
index 00000000..95173e8f
--- /dev/null
+++ b/R/duplicates.R
@@ -0,0 +1,187 @@
+#' check if data.table contains duplicated data
+#' 
+#' An auxiliary function that checks for duplicates in the data.table (or its subset)
+#' 
+#' @param dt data.table
+#' @param col_names charvec with columns to be used for subsetting
+#' @examples
+#' dt <- data.table::data.table(a = c(1, 2, 3), b = c(3, 2, 2))
+#' has_dt_duplicated_rows(dt, "b")
+#' @return logical flag indicating if a dt contains duplicated rows or not
+#' @keywords duplicates
+#'
+#' @export
+#' 
+has_dt_duplicated_rows <- function(dt, col_names = NULL) {
+  checkmate::assert_data_table(dt)
+  checkmate::assert_character(col_names, null.ok = TRUE)
+  
+  if (is.null(col_names)) {
+    anyDuplicated(dt) != 0
+  } else {
+    checkmate::assert_subset(col_names, colnames(dt))
+    anyDuplicated(dt, by = col_names) != 0
+  }
+  
+}
+
+#' get columns in the assay data required to have unique data
+#' 
+#' get columns in the assay data required to have unique (non-duplicated) data
+#' 
+#' @param dt data.table with assay data
+#' @examples
+#' sdata <- get_synthetic_data("finalMAE_small")
+#' smetrics_data <- convert_se_assay_to_dt(sdata[[1]], "Metrics")
+#' get_assay_req_uniq_cols(smetrics_data)
+#' @return charvec with columns required to have unique data
+#' @keywords duplicates
+#' @export
+#' 
+get_assay_req_uniq_cols <- function(dt) {
+  
+  checkmate::assert_data_table(dt)
+  col_ids <- get_settings_from_json(
+    "assay_dt_req_uniq_col_ids",
+    system.file(package = "gDRutils", "settings.json")
+  )
+  
+  # check with both pretiffied and unprettified version of ids
+  col_names_p <- unlist(get_prettified_identifiers(col_ids, simplify = FALSE))
+  col_names_up <- as.character(get_env_identifiers(col_ids, simplify = FALSE))
+  col_names <- unique(c(col_names_p, col_names_up))
+  
+  intersect(col_names, names(dt))
+}
+
+#' check if assay data contains duplicated data
+#' 
+#' An auxiliary function that checks for duplicates in the assay data
+#' 
+#' @param dt data.table with assay data
+#' 
+#' @return logical flag indicating if a dt contains duplicated rows or not
+#' @keywords duplicates
+#' @examples
+#' sdata <- get_synthetic_data("finalMAE_small")
+#' smetrics_data <- convert_se_assay_to_dt(sdata[[1]], "Metrics")
+#' has_assay_dt_duplicated_rows(smetrics_data)
+#' @export
+#' 
+has_assay_dt_duplicated_rows <- function(dt) { 
+
+  checkmate::assert_data_table(dt)
+  
+  col_names <- get_assay_req_uniq_cols(dt)
+  has_dt_duplicated_rows(dt, col_names)
+
+}
+
+
+#' Helper function to find duplicated rows
+#'
+#' @param x DataFrame or data.table
+#' @param col_names character vector, columns in which duplication are searched for
+#' @param output string with the output format to be returned - 
+#' one of "index" (index of duplicates) or "data" (subset of input data with duplicates)
+#' @examples
+#' dt <- data.table::data.table(a = c(1, 2, 3), b = c(3, 2, 2))
+#' get_duplicated_rows(dt, "b")
+#' get_duplicated_rows(dt, "b", output = "data")
+#' @return integer vector or data.table with duplicated rows
+#' @keywords duplicates
+#' @export
+get_duplicated_rows <- function(x, 
+                                col_names = NULL, 
+                                output = "index") {
+  
+  checkmate::assertMultiClass(x, c("data.table", "DataFrame"))
+  checkmate::assert_true(all(col_names %in% colnames(x)))
+  checkmate::assert_choice(output, c("index", "data"))
+  
+  
+  if (!is.null(col_names)) {
+    sub_x <- subset(x, select = col_names)
+  } else {
+  sub_x <- x
+ }
+  idx <- which(duplicated(sub_x) | duplicated(sub_x, fromLast = TRUE))
+  
+  out <- if (output == "index") {
+    idx
+  } else {
+    if (length(idx)) {
+      x[idx, ]
+    } else {
+      x[0, ]
+    }
+  }
+  out
+}
+
+#' Helper function to find duplicated rows in assay data
+#'
+#' @param dt data.table
+#' @param output string with the output format to be returned
+#' @return integer vector or data.table with duplicated rows
+#' @examples
+#' sdata <- get_synthetic_data("finalMAE_small")
+#' smetrics_data <- convert_se_assay_to_dt(sdata[[1]], "Metrics")
+#' get_assay_dt_duplicated_rows(smetrics_data, output = "data")
+#' get_assay_dt_duplicated_rows(smetrics_data)
+#' @keywords duplicates
+#' @export
+get_assay_dt_duplicated_rows <- function(dt, output = "index") {
+  
+  checkmate::assert_data_table(dt)
+  
+  col_names <- get_assay_req_uniq_cols(dt)
+  
+  get_duplicated_rows(dt, col_names, output = output)
+}
+
+
+#' throw message if assay data.table contains duplicated rows
+#' 
+#' An auxiliary function that checks for duplicated rows in assay data.table, 
+#' In case of duplicates it throws a message. The messsage function is by default `stop()` 
+#' The message function can be customized with `msg_f` parameter
+#' 
+#' @param dt data.table with assay data
+#' @param assay_name string with the name of the assay
+#' @param msg_f function to be used to throw the message
+#' @param preview_max_numb number of rows to preview if duplicates found
+#' @examples
+#' sdata <- get_synthetic_data("finalMAE_small")
+#' smetrics_data <- convert_se_assay_to_dt(sdata[[1]], "Metrics")
+#' throw_msg_if_duplicates(smetrics_data, assay_name = "Metrics", msg_f = futile.logger::flog.info)
+#' @return NULL
+#' @keywords duplicates
+#'
+#' @export
+#' 
+throw_msg_if_duplicates <- function(dt, assay_name = "unknown", msg_f = stop, preview_max_numb = 4) {
+
+  checkmate::assert_data_table(dt)
+  checkmate::assert_string(assay_name)
+  checkmate::assert_function(msg_f)
+  checkmate::assert_number(preview_max_numb)
+
+  if (has_assay_dt_duplicated_rows(dt)) { 
+
+    dup_dt <- get_assay_dt_duplicated_rows(dt, output = "data")
+    preview_numb <- min(c(preview_max_numb, NROW(dup_dt)))
+   
+     msg <- sprintf(
+          "The %i ouf of %i rows are duplicated in the assay '%s'",
+          NROW(dup_dt),
+          NROW(dt),
+          assay_name)
+     msg2 <- sprintf(" when checking uniquness with the following set of columns: '%s'. ",
+          toString(get_assay_req_uniq_cols(dt)))
+     msg3 <- sprintf("Here is the preview of the first %i duplicated rows in JSON format: '%s'",
+          preview_numb,
+          jsonlite::toJSON(dup_dt[seq(preview_numb), ]))
+     msg_f(paste0(msg, msg2, msg3))
+  }
+}
diff --git a/R/utils.R b/R/utils.R
index 85895572..e96d68c2 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -504,25 +504,6 @@ average_biological_replicates_dt <- function(
   
   unique(data, by = group_by)
 }
-#' Helper function to find duplicated rows
-#'
-#' @param x data frame
-#' @param col_names character vector, columns in which duplication are searched for
-#' @return integer vector
-#' @examples
-#' dt <- data.table::data.table(a = c(1, 2, 3), b = c(3, 2, 2))
-#' get_duplicated_rows(dt, "b")
-#' @keywords package_utils
-#' @export
-get_duplicated_rows <- function(x, col_names = NULL) {
-  checkmate::assertMultiClass(x, c("data.table", "DataFrame"))
-  checkmate::assert_true(all(col_names %in% colnames(x)))
-  
-  if (!is.null(col_names)) {
-    x <- subset(x, select = col_names)
-  }
-  which(duplicated(x) | duplicated(x, fromLast = TRUE))
-}
 
 #' Checks if \code{se} is combo dataset.
 #'
diff --git a/_pkgdown.yml b/_pkgdown.yml
index 7fbe03fb..37788252 100644
--- a/_pkgdown.yml
+++ b/_pkgdown.yml
@@ -39,6 +39,9 @@ reference:
 - title: Standardize MAE
 - contents:
   - has_keyword("standardize_MAE")
+- title: Duplicates
+- contents:
+  - has_keyword("duplicates")
 - title: Utils
 - contents:
   - has_keyword("package_utils")
diff --git a/inst/settings.json b/inst/settings.json
index 5f9a461c..1ed6d4c5 100644
--- a/inst/settings.json
+++ b/inst/settings.json
@@ -22,5 +22,13 @@
         "pos_y_ref": "pos_y_ref",
         "log10_ratio": "log10_ratio_conc",
         "log2_CI": "log2_CI"
-    }
-}
\ No newline at end of file
+    },
+    "assay_dt_req_uniq_col_ids": [
+        "drug_name",
+        "drug_name2",
+        "cellline_name",
+        "concentration2",
+        "duration",
+        "data_source"
+    ]
+}
diff --git a/man/get_assay_dt_duplicated_rows.Rd b/man/get_assay_dt_duplicated_rows.Rd
new file mode 100644
index 00000000..43111dc0
--- /dev/null
+++ b/man/get_assay_dt_duplicated_rows.Rd
@@ -0,0 +1,26 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/duplicates.R
+\name{get_assay_dt_duplicated_rows}
+\alias{get_assay_dt_duplicated_rows}
+\title{Helper function to find duplicated rows in assay data}
+\usage{
+get_assay_dt_duplicated_rows(dt, output = "index")
+}
+\arguments{
+\item{dt}{data.table}
+
+\item{output}{string with the output format to be returned}
+}
+\value{
+integer vector or data.table with duplicated rows
+}
+\description{
+Helper function to find duplicated rows in assay data
+}
+\examples{
+sdata <- get_synthetic_data("finalMAE_small")
+smetrics_data <- convert_se_assay_to_dt(sdata[[1]], "Metrics")
+get_assay_dt_duplicated_rows(smetrics_data, output = "data")
+get_assay_dt_duplicated_rows(smetrics_data)
+}
+\keyword{duplicates}
diff --git a/man/get_assay_req_uniq_cols.Rd b/man/get_assay_req_uniq_cols.Rd
new file mode 100644
index 00000000..91ea6ff0
--- /dev/null
+++ b/man/get_assay_req_uniq_cols.Rd
@@ -0,0 +1,23 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/duplicates.R
+\name{get_assay_req_uniq_cols}
+\alias{get_assay_req_uniq_cols}
+\title{get columns in the assay data required to have unique data}
+\usage{
+get_assay_req_uniq_cols(dt)
+}
+\arguments{
+\item{dt}{data.table with assay data}
+}
+\value{
+charvec with columns required to have unique data
+}
+\description{
+get columns in the assay data required to have unique (non-duplicated) data
+}
+\examples{
+sdata <- get_synthetic_data("finalMAE_small")
+smetrics_data <- convert_se_assay_to_dt(sdata[[1]], "Metrics")
+get_assay_req_uniq_cols(smetrics_data)
+}
+\keyword{duplicates}
diff --git a/man/get_duplicated_rows.Rd b/man/get_duplicated_rows.Rd
index 767f0902..f93f8800 100644
--- a/man/get_duplicated_rows.Rd
+++ b/man/get_duplicated_rows.Rd
@@ -1,18 +1,21 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/utils.R
+% Please edit documentation in R/duplicates.R
 \name{get_duplicated_rows}
 \alias{get_duplicated_rows}
 \title{Helper function to find duplicated rows}
 \usage{
-get_duplicated_rows(x, col_names = NULL)
+get_duplicated_rows(x, col_names = NULL, output = "index")
 }
 \arguments{
-\item{x}{data frame}
+\item{x}{DataFrame or data.table}
 
 \item{col_names}{character vector, columns in which duplication are searched for}
+
+\item{output}{string with the output format to be returned -
+one of "index" (index of duplicates) or "data" (subset of input data with duplicates)}
 }
 \value{
-integer vector
+integer vector or data.table with duplicated rows
 }
 \description{
 Helper function to find duplicated rows
@@ -20,5 +23,6 @@ Helper function to find duplicated rows
 \examples{
 dt <- data.table::data.table(a = c(1, 2, 3), b = c(3, 2, 2))
 get_duplicated_rows(dt, "b")
+get_duplicated_rows(dt, "b", output = "data")
 }
-\keyword{package_utils}
+\keyword{duplicates}
diff --git a/man/has_assay_dt_duplicated_rows.Rd b/man/has_assay_dt_duplicated_rows.Rd
new file mode 100644
index 00000000..0c67d6ab
--- /dev/null
+++ b/man/has_assay_dt_duplicated_rows.Rd
@@ -0,0 +1,23 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/duplicates.R
+\name{has_assay_dt_duplicated_rows}
+\alias{has_assay_dt_duplicated_rows}
+\title{check if assay data contains duplicated data}
+\usage{
+has_assay_dt_duplicated_rows(dt)
+}
+\arguments{
+\item{dt}{data.table with assay data}
+}
+\value{
+logical flag indicating if a dt contains duplicated rows or not
+}
+\description{
+An auxiliary function that checks for duplicates in the assay data
+}
+\examples{
+sdata <- get_synthetic_data("finalMAE_small")
+smetrics_data <- convert_se_assay_to_dt(sdata[[1]], "Metrics")
+has_assay_dt_duplicated_rows(smetrics_data)
+}
+\keyword{duplicates}
diff --git a/man/has_dt_duplicated_rows.Rd b/man/has_dt_duplicated_rows.Rd
new file mode 100644
index 00000000..7e7daa0f
--- /dev/null
+++ b/man/has_dt_duplicated_rows.Rd
@@ -0,0 +1,24 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/duplicates.R
+\name{has_dt_duplicated_rows}
+\alias{has_dt_duplicated_rows}
+\title{check if data.table contains duplicated data}
+\usage{
+has_dt_duplicated_rows(dt, col_names = NULL)
+}
+\arguments{
+\item{dt}{data.table}
+
+\item{col_names}{charvec with columns to be used for subsetting}
+}
+\value{
+logical flag indicating if a dt contains duplicated rows or not
+}
+\description{
+An auxiliary function that checks for duplicates in the data.table (or its subset)
+}
+\examples{
+dt <- data.table::data.table(a = c(1, 2, 3), b = c(3, 2, 2))
+has_dt_duplicated_rows(dt, "b")
+}
+\keyword{duplicates}
diff --git a/man/throw_msg_if_duplicates.Rd b/man/throw_msg_if_duplicates.Rd
new file mode 100644
index 00000000..ad80b3c5
--- /dev/null
+++ b/man/throw_msg_if_duplicates.Rd
@@ -0,0 +1,33 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/duplicates.R
+\name{throw_msg_if_duplicates}
+\alias{throw_msg_if_duplicates}
+\title{throw message if assay data.table contains duplicated rows}
+\usage{
+throw_msg_if_duplicates(
+  dt,
+  assay_name = "unknown",
+  msg_f = stop,
+  preview_max_numb = 4
+)
+}
+\arguments{
+\item{dt}{data.table with assay data}
+
+\item{assay_name}{string with the name of the assay}
+
+\item{msg_f}{function to be used to throw the message}
+
+\item{preview_max_numb}{number of rows to preview if duplicates found}
+}
+\description{
+An auxiliary function that checks for duplicated rows in assay data.table,
+In case of duplicates it throws a message. The messsage function is by default \code{stop()}
+The message function can be customized with \code{msg_f} parameter
+}
+\examples{
+sdata <- get_synthetic_data("finalMAE_small")
+smetrics_data <- convert_se_assay_to_dt(sdata[[1]], "Metrics")
+throw_msg_if_duplicates(smetrics_data, assay_name = "Metrics", msg_f = futile.logger::flog.info)
+}
+\keyword{duplicates}
diff --git a/tests/testthat/test-duplicates.R b/tests/testthat/test-duplicates.R
new file mode 100644
index 00000000..37f870d6
--- /dev/null
+++ b/tests/testthat/test-duplicates.R
@@ -0,0 +1,88 @@
+test_that("has_dt_duplicated_rows works as expected", {
+  
+  dt_iris <- data.table::data.table(iris)
+  expect_true(has_dt_duplicated_rows(dt_iris))
+  expect_false(has_dt_duplicated_rows(dt_iris[1:100, ]))
+  
+  expect_true(has_dt_duplicated_rows(dt_iris[1:10, ], col_names = c("Sepal.Length", "Species")))
+  expect_error(has_dt_duplicated_rows(iris), "Assertion on 'dt' failed")
+  expect_error(
+    has_dt_duplicated_rows(dt_iris, col_names = "invalid_value"),
+    "Assertion on 'col_names' failed"
+  )
+  
+})
+
+test_that("get_duplicated_rows works as expected", {
+  DF1co <- S4Vectors::DataFrame("Gnumber" = c("G0123456.1-1", "G0123456.2-2", "G1234567.1-1"),
+                                "DrugName" = c("drug_name1", "drug_name1", "drug_name2"),
+                                "Gnumber_2" = c("G9876543.1-1", "G9876543.1-1", "G9876543.1-1"),
+                                "DrugName_2" = c("codrug_name1", "codrug_name1", "codrug_name1"),
+                                "Concentration_2" = c("untreated", "untreated", "untreated"))
+  
+  
+  # single column
+  expect_equal(
+    get_duplicated_rows(DF1co, col_names = "DrugName"),
+    c(1, 2)
+  )
+  # single column with only duplicates
+  expect_equal(
+    get_duplicated_rows(DF1co, col_names = "DrugName_2"),
+    c(1, 2, 3)
+  )
+  # single column without duplicates
+  expect_equal(
+    get_duplicated_rows(DF1co, col_names = c("Gnumber")),
+    integer()
+  )
+  # multiple columns
+  expect_equal(
+    get_duplicated_rows(DF1co, col_names = c("DrugName_2", "DrugName")),
+    c(1, 2)
+  )
+  # single column with non-default output
+  expect_equal(
+    get_duplicated_rows(DF1co, col_names = "DrugName", output = "data"),
+    DF1co[1:2, ]
+  )
+  
+  expect_error(get_duplicated_rows(DF1co, c("DrugName", "Fake Column")),
+               "Assertion on 'all(col_names %in% colnames(x))' failed: Must be TRUE.", fixed = TRUE)
+})
+
+test_that("[has|get]_assay_dt_duplicated_rows works as expected", {
+  
+  sdata <- get_synthetic_data("finalMAE_small")
+  smetrics_data <- convert_se_assay_to_dt(sdata[[1]], "Metrics")
+  smetrics_data_f <- gDRutils::flatten(
+    smetrics_data,
+    groups = c("normalization_type", "fit_source"),
+    wide_cols = gDRutils::get_header("response_metrics")
+  )
+  expect_true(has_assay_dt_duplicated_rows(smetrics_data))
+  expect_false(has_assay_dt_duplicated_rows(smetrics_data_f))
+  
+  expect_equal(get_assay_dt_duplicated_rows(smetrics_data), 1:200)
+  expect_equal(dim(smetrics_data), dim(get_assay_dt_duplicated_rows(smetrics_data, output = "data")))
+  expect_equal(get_assay_dt_duplicated_rows(smetrics_data_f), integer(0))
+  empty_dt <- get_assay_dt_duplicated_rows(smetrics_data_f, output = "data")
+  expect_true(nrow(empty_dt) == 0)
+  expect_is(empty_dt, "data.table")
+})
+
+test_that("throw_msg_if_duplicates works as expected", {
+ 
+  sdata <- get_synthetic_data("finalMAE_small")
+  smetrics_data <- convert_se_assay_to_dt(sdata[[1]], "Metrics")
+  smetrics_data_f <- gDRutils::flatten(
+    smetrics_data,
+    groups = c("normalization_type", "fit_source"),
+    wide_cols = gDRutils::get_header("response_metrics")
+  )
+  
+  
+  exp_msg <- "rows are duplicated"
+  expect_error(throw_msg_if_duplicates(smetrics_data, "Metrics"), exp_msg)
+  expect_warning(throw_msg_if_duplicates(smetrics_data, "Metrics", msg_f = warning), exp_msg)
+})
diff --git a/tests/testthat/test-utils.R b/tests/testthat/test-utils.R
index 143fa9f4..4c61b0a5 100644
--- a/tests/testthat/test-utils.R
+++ b/tests/testthat/test-utils.R
@@ -255,39 +255,6 @@ test_that("average_biological_replicates_dt works as expected", {
   
 })
 
-test_that("get_duplicated_rows works as expected", {
-  DF1co <- S4Vectors::DataFrame("Gnumber" = c("G0123456.1-1", "G0123456.2-2", "G1234567.1-1"),
-                                "DrugName" = c("drug_name1", "drug_name1", "drug_name2"),
-                                "Gnumber_2" = c("G9876543.1-1", "G9876543.1-1", "G9876543.1-1"),
-                                "DrugName_2" = c("codrug_name1", "codrug_name1", "codrug_name1"),
-                                "Concentration_2" = c("untreated", "untreated", "untreated"))
-  
-  
-  # single column
-  expect_equal(
-    get_duplicated_rows(DF1co, col_names = "DrugName"),
-    c(1, 2)
-  )
-  # single column with only duplicates
-  expect_equal(
-    get_duplicated_rows(DF1co, col_names = "DrugName_2"),
-    c(1, 2, 3)
-  )
-  # single column without duplicates
-  expect_equal(
-    get_duplicated_rows(DF1co, col_names = c("Gnumber")),
-    integer()
-  )
-  # multiple columns
-  expect_equal(
-    get_duplicated_rows(DF1co, col_names = c("DrugName_2", "DrugName")),
-    c(1, 2)
-  )
-  
-  expect_error(get_duplicated_rows(DF1co, c("DrugName", "Fake Column")),
-               "Assertion on 'all(col_names %in% colnames(x))' failed: Must be TRUE.", fixed = TRUE)
-})
-
 test_that("has_single_codrug_data works as expected", {
   expect_false(has_single_codrug_data("un_col"))
   expect_true(has_single_codrug_data(get_prettified_identifiers(c(