code: def test_edge_starting_from_attribute_throws_exception(self):
      variable_graph = nx.MultiDiGraph()
      variable_graph.add_node("x")
      variable_graph.add_node("y")
      variable_graph.add_edge("x", "y", type="employee")
  
      name = Thing(
          "V123", "name", "attribute", value_type="string", value="Bob"
      )
      employment = Thing("V456", "employment", "relation")
      concept_dict = {"x": name, "y": employment}
  
      with self.assertRaises(ValueError) as context:
          _ = concept_dict_to_networkx(concept_dict, variable_graph)
  
      self.assertEqual(
          "An edge in the variable_graph originates from a non-relation, check the variable_graph!",
          str(context.exception),
      )
  
file_path: typedb-ml/typedb_ml/networkx/concept_dict_to_networkx_test.py
imports: import unittest
  import networkx
  from typedb_ml.typedb.thing import Thing
  from typedb_ml.networkx.concept_dict_to_networkx import concept_dict_to_networkx
  from typedb_ml.networkx.graph_test_case import GraphTestCase
label_desc: Use image node_id 7 for calling the TestConceptDictToTypeDBGraph obj's underlying member method code with example usage: obj.test_edge_starting_from_attribute_throws_exception() without return types