code: def test_selfloops(self):
      G0 = nx.Graph()
      G1 = nx.Graph()
      G1.add_edges_from((("A", "A"), ("A", "B")))
      G2 = nx.Graph()
      G2.add_edges_from((("A", "B"), ("B", "B")))
      G3 = nx.Graph()
      G3.add_edges_from((("A", "A"), ("A", "B"), ("B", "B")))
  
      assert graph_edit_distance(G0, G0) == 0
      assert graph_edit_distance(G0, G1) == 4
      assert graph_edit_distance(G1, G0) == 4
      assert graph_edit_distance(G0, G2) == 4
      assert graph_edit_distance(G2, G0) == 4
      assert graph_edit_distance(G0, G3) == 5
      assert graph_edit_distance(G3, G0) == 5
  
      assert graph_edit_distance(G1, G1) == 0
      assert graph_edit_distance(G1, G2) == 0
      assert graph_edit_distance(G2, G1) == 0
      assert graph_edit_distance(G1, G3) == 1
      assert graph_edit_distance(G3, G1) == 1
  
      assert graph_edit_distance(G2, G2) == 0
      assert graph_edit_distance(G2, G3) == 1
      assert graph_edit_distance(G3, G2) == 1
  
      assert graph_edit_distance(G3, G3) == 0
  
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 11 for calling the TestSimilarity obj's underlying member method code with example usage: obj.test_selfloops() without return types