code: def testBcast(self):
      rank = self.INTERCOMM.Get_rank()
      size = self.INTERCOMM.Get_size()
      rsize = self.INTERCOMM.Get_remote_size()
      for smess in messages + [messages]:
          for color in [0, 1]:
              if self.COLOR == color:
                  for root in range(size):
                      if root == rank:
                          rmess = self.INTERCOMM.bcast(
                              smess, root=MPI.ROOT
                          )
                      else:
                          rmess = self.INTERCOMM.bcast(
                              None, root=MPI.PROC_NULL
                          )
                      self.assertIsNone(rmess)
              else:
                  for root in range(rsize):
                      rmess = self.INTERCOMM.bcast(None, root=root)
                      self.assertEqual(rmess, smess)
  
imports: from mpi4py import MPI
  import mpiunittest
  from functools import reduce
label_desc: Use image node_id 4 for calling the BaseTestCCOObjInter obj's underlying member method code with example usage: obj.testBcast() without return types