code: def testConstructor(self):
      op = MPI.Op()
      self.assertFalse(op)
      self.assertEqual(op, MPI.OP_NULL)
  
imports: from mpi4py import MPI
  import mpiunittest
label_desc: Use image node_id 1 for calling the TestOp obj's underlying member method code with example usage: obj.testConstructor() without return types