code: def testAlltoallw2(self):
      size = self.COMM.Get_size()
      rank = self.COMM.Get_rank()
      for array, typecode in arrayimpl.loop():
          for count in range(size):
              rbuf = array(-1, typecode, size * size)
              for i in range(size):
                  for j in range(count):
                      rbuf[i * size + j] = rank
              rdt = rbuf.mpidtype
              rdsp = list(
                  range(0, size * size * rdt.extent, size * rdt.extent)
              )
              rmsg = (rbuf.as_raw(), [count] * size, rdsp, [rdt] * size)
              try:
                  self.COMM.Alltoallw(MPI.IN_PLACE, rmsg)
              except NotImplementedError:
                  self.skipTest("mpi-alltoallw")
              for i in range(size):
                  row = rbuf[i * size : (i + 1) * size]
                  a, b = row[:count], row[count:]
                  for va in a:
                      check_a = arrayimpl.scalar(i)
                      self.assertEqual(va, check_a)
                  for vb in b:
                      check_b = arrayimpl.scalar(-1)
                      self.assertEqual(vb, check_b)
  
imports: from mpi4py import MPI
  import mpiunittest
  import arrayimpl
label_desc: Use image node_id 3 for calling the BaseTestCCOVecInplace obj's underlying member method code with example usage: obj.testAlltoallw2() without return types