code: def testOneExtraNodeAndEdge(self):
      G1 = nx.Graph()
      G1.add_node("A", label="A")
      G1.add_node("B", label="B")
      G1.add_edge("A", "B", label="a-b")
      G2 = nx.Graph()
      G2.add_node("A", label="A")
      G2.add_node("B", label="B")
      G2.add_node("C", label="C")
      G2.add_edge("A", "B", label="a-b")
      G2.add_edge("A", "C", label="a-c")
      assert (
          graph_edit_distance(
              G1, G2, node_match=nmatch, edge_match=ematch
          )
          == 2
      )
  
imports: import pytest
  import networkx
  from networkx.algorithms.similarity import graph_edit_distance, optimal_edit_paths, optimize_graph_edit_distance
  from networkx.generators.classic import circular_ladder_graph, cycle_graph, path_graph, wheel_graph
label_desc: Use image node_id 21 for calling the TestSimilarity obj's underlying member method code with example usage: obj.testOneExtraNodeAndEdge() without return types