code: def testPickle(self):
      from pickle import dumps, loads
  
      COMM = self.COMM
      if COMM in (MPI.COMM_SELF, MPI.COMM_WORLD):
          comm = loads(dumps(COMM))
          self.assertIs(comm, COMM)
          comm = loads(dumps(MPI.Intracomm(COMM)))
          self.assertIsNot(comm, COMM)
          self.assertEqual(comm, COMM)
      else:
          self.assertRaises(ValueError, dumps, COMM)
  
imports: from mpi4py import MPI
  import mpiunittest
label_desc: Use image node_id 23 for calling the BaseTestComm obj's underlying member method code with example usage: obj.testPickle() without return types