code: def testPickle(self):
      from pickle import dumps, loads
  
      group_empty = loads(dumps(MPI.GROUP_EMPTY))
      self.assertIs(group_empty, MPI.GROUP_EMPTY)
      group_empty = loads(dumps(MPI.Group(MPI.GROUP_EMPTY)))
      self.assertIsNot(group_empty, MPI.GROUP_EMPTY)
      self.assertEqual(group_empty, MPI.GROUP_EMPTY)
  
imports: from mpi4py import MPI
  import mpiunittest
label_desc: Use image node_id 6 for calling the TestGroupEmpty obj's underlying member method code with example usage: obj.testPickle() without return types