code: def testConstants(self):
      import pickle
  
      names = (
          "BOTTOM",
          "IN_PLACE",
          "BUFFER_AUTOMATIC",
      )
      for name in names:
          constant = getattr(MPI, name)
          self.assertEqual(repr(constant), name)
          self.assertEqual(memoryview(constant).nbytes, 0)
          self.assertEqual(MPI.Get_address(constant), constant)
          if sys.implementation.name != "pypy":
              self.assertIsNone(memoryview(constant).obj)
          with self.assertRaises(ValueError):
              type(constant)(constant + 1)
          self.assertEqual(repr(constant), name)
          self.assertEqual(constant.__reduce__(), name)
          for protocol in range(pickle.HIGHEST_PROTOCOL):
              value = pickle.loads(pickle.dumps(constant, protocol))
              self.assertIs(type(value), type(constant))
              self.assertEqual(value, constant)
  
imports: from mpi4py import MPI
  import mpiunittest
  import ctypes
  import operator
  import weakref
  import sys
label_desc: Use image node_id 10 for calling the TestObjModel obj's underlying member method code with example usage: obj.testConstants() without return types