code: def test__LCF_graph(self):
      # If n<=0, then return the null_graph
      G = nx.LCF_graph(-10, [1, 2], 100)
      assert is_isomorphic(G, null)
      G = nx.LCF_graph(0, [1, 2], 3)
      assert is_isomorphic(G, null)
      G = nx.LCF_graph(0, [1, 2], 10)
      assert is_isomorphic(G, null)
  
      # Test that LCF(n,[],0) == cycle_graph(n)
      for a, b, c in [
          (5, [], 0),
          (10, [], 0),
          (5, [], 1),
          (10, [], 10),
      ]:
          G = nx.LCF_graph(a, b, c)
          assert is_isomorphic(G, nx.cycle_graph(a))
  
      # Generate the utility graph K_{3,3}
      G = nx.LCF_graph(6, [3, -3], 3)
      utility_graph = nx.complete_bipartite_graph(3, 3)
      assert is_isomorphic(G, utility_graph)
  
imports: import pytest
  import networkx
  from networkx.algorithms.isomorphism.isomorph import graph_could_be_isomorphic
label_desc: Use image node_id 1 for calling the TestGeneratorsSmall obj's underlying member method code with example usage: obj.test__LCF_graph() without return types