code: def test_first_graph_empty(self, graph_type):
      G = graph_type()
      H = graph_type([(0, 1)])
      assert vf2pp_isomorphism(G, H) is None
  
imports: import itertools
  import pytest
  import networkx
  from networkx import vf2pp_is_isomorphic, vf2pp_isomorphism
label_desc: Use image node_id 2 for calling the TestAllGraphTypesEdgeCases obj's underlying member method code with example usage: obj.test_first_graph_empty(graph_type) without return types