code: def testShrink(self):
      comm = self.COMM
      shrink = comm.Shrink()
      self.assertEqual(comm.Get_size(), shrink.Get_size())
      self.assertEqual(comm.Get_rank(), shrink.Get_rank())
      if shrink.Is_inter():
          self.assertEqual(
              comm.Get_remote_size(), shrink.Get_remote_size()
          )
      shrink.Free()
  
imports: from mpi4py import MPI
  import mpiunittest
  import warnings
  import struct
label_desc: Use image node_id 9 for calling the BaseTestULFM obj's underlying member method code with example usage: obj.testShrink() without return types