fix tests and mypy errors

pyhgf/utils/add_parent.py

@@ -3,7 +3,7 @@
 from typing import Dict, Tuple
 
 from pyhgf.typing import AdjacencyLists, Edges
-from pyhgf.utils import add_edges
+from pyhgf.utils.add_edges import add_edges
 
 
 def add_parent(
@@ -21,7 +21,7 @@ def add_parent(
         The index of the node you want to connect a new parent node to.
     coupling_type :
         The type of coupling you want between the existing node and it's new parent.
-        Can be either "value" or "volatility".
+        Can be either `"value"` or `"volatility"`.
     mean :
         The mean value of the new parent node.
 

tests/test_utils.py

@@ -93,6 +93,7 @@ def test_set_update_sequence():
     assert len(predictions) == 1
     assert len(updates) == 3
 
+
 def test_add_parent():
     """Test the add_parent function."""
     network = (
@@ -101,16 +102,18 @@ def test_add_parent():
         .add_nodes(value_children=2)
         .add_nodes(value_children=3)
     )
+    attributes, edges, _ = network.get_network()
     new_attributes, new_edges = add_parent(attributes, edges, 1, "volatility", 1.0)
 
     assert len(new_attributes) == 8
     assert len(new_edges) == 7
 
     new_attributes, new_edges = add_parent(attributes, edges, 1, "value", 1.0)
 
-    assert len(new_attributes) == 9
-    assert len(new_edges) == 8
-
+    assert len(new_attributes) == 8
+    assert len(new_edges) == 7
+
+
 def test_remove_node():
     """Test the remove_node function."""
     network = (