code: def testConstructor(self):
      preq = self.COMM.Send_init(b"", MPI.PROC_NULL, 0)
      dupe = MPI.Prequest(preq)
      self.assertIs(type(dupe), MPI.Prequest)
      self.assertEqual(dupe, preq)
      dupe = MPI.Prequest.fromhandle(preq.handle)
      self.assertIs(type(dupe), MPI.Prequest)
      self.assertEqual(dupe, preq)
      dupe = MPI.Prequest.f2py(preq.py2f())
      self.assertIs(type(dupe), MPI.Prequest)
      self.assertEqual(dupe, preq)
      dupe = MPI.Request(preq)
      self.assertIs(type(dupe), MPI.Request)
      self.assertEqual(dupe, preq)
      with self.assertRaises(TypeError):
          dupe = MPI.Grequest(preq)
      preq.Start()
      preq.Wait()
      preq.Free()
  
imports: from mpi4py import MPI
  import mpiunittest
  import itertools
  import arrayimpl
label_desc: Use image node_id 9 for calling the BaseTestP2PBuf obj's underlying member method code with example usage: obj.testConstructor() without return types