code: def testPostWait(self):
      self.WIN.Post(MPI.GROUP_EMPTY)
      self.WIN.Wait()
  
imports: from mpi4py import MPI
  import mpiunittest
  import contextlib
  import arrayimpl
  import sys
label_desc: Use image node_id 16 for calling the BaseTestRMA obj's underlying member method code with example usage: obj.testPostWait() without return types