code: def testRecvObjArg(self):
      comm = self.COMM
      rank = comm.Get_rank()
      req1 = comm.isend("42", rank)
      req2 = comm.isend([42], rank)
      with warnings.catch_warnings():
          warnings.simplefilter("error")
          with self.assertRaises(UserWarning):
              comm.recv(bytearray(0), MPI.PROC_NULL)
          warnings.simplefilter("ignore")
          obj = comm.recv(128, rank)
          self.assertEqual(obj, "42")
          req1.wait()
          obj = comm.recv(bytearray(128), rank)
          self.assertEqual(obj, [42])
          req2.wait()
  
imports: from mpi4py import MPI
  import mpiunittest
  import threading
  import warnings
  import sys
label_desc: Use image node_id 22 for calling the BaseTestP2PObj obj's underlying member method code with example usage: obj.testRecvObjArg() without return types