code: def test_non_line_graphs(self):
      # Tests several known non-line graphs for impossibility
      # Adapted from L.W.Beineke, "Characterizations of derived graphs"
  
      # claw graph
      claw = nx.star_graph(3)
      pytest.raises(nx.NetworkXError, nx.inverse_line_graph, claw)
  
      # wheel graph with 6 nodes
      wheel = nx.wheel_graph(6)
      pytest.raises(nx.NetworkXError, nx.inverse_line_graph, wheel)
  
      # K5 with one edge remove
      K5m = nx.complete_graph(5)
      K5m.remove_edge(0, 1)
      pytest.raises(nx.NetworkXError, nx.inverse_line_graph, K5m)
  
      # graph without any odd triangles (contains claw as induced subgraph)
      G = nx.compose(
          nx.path_graph(2), nx.complete_bipartite_graph(2, 3)
      )
      pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
  
      ## Variations on a diamond graph
  
      # Diamond + 2 edges (+ "roof")
      G = nx.diamond_graph()
      G.add_edges_from([(4, 0), (5, 3)])
      pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
      G.add_edge(4, 5)
      pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
  
      # Diamond + 2 connected edges
      G = nx.diamond_graph()
      G.add_edges_from([(4, 0), (4, 3)])
      pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
  
      # Diamond + K3 + one edge (+ 2*K3)
      G = nx.diamond_graph()
      G.add_edges_from([(4, 0), (4, 1), (4, 2), (5, 3)])
      pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
      G.add_edges_from([(5, 1), (5, 2)])
      pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
  
      # 4 triangles
      G = nx.diamond_graph()
      G.add_edges_from([(4, 0), (4, 1), (5, 2), (5, 3)])
      pytest.raises(nx.NetworkXError, nx.inverse_line_graph, G)
  
imports: import pytest
  import networkx
  from networkx.generators import line
  from networkx.utils import edges_equal
label_desc: Use image node_id 11 for calling the TestGeneratorInverseLine obj's underlying member method code with example usage: obj.test_non_line_graphs() without return types