code: def testConstructorGraphcomm(self):
      comm = MPI.COMM_SELF
      graph = comm.Create_graph([0, 1], [0])
      with self.assertRaises(TypeError):
          MPI.Cartcomm(graph)
      with self.assertRaises(TypeError):
          MPI.Distgraphcomm(graph)
      graph.Free()
  
imports: from mpi4py import MPI
  import mpiunittest
label_desc: Use image node_id 3 for calling the TestTopoConstructor obj's underlying member method code with example usage: obj.testConstructorGraphcomm() without return types