code: def testArgsOnlyAtRoot(self):
      self.COMM.Barrier()
      if self.COMM.Get_rank() == self.ROOT:
          count = 2 + (self.COMM.Get_size() == 0)
          COMMAND = [self.COMMAND] * count
          ARGS = [self.ARGS] * len(COMMAND)
          MAXPROCS = list(range(1, len(COMMAND) + 1))
          INFO = [MPI.INFO_NULL] * len(COMMAND)
          child = self.COMM.Spawn_multiple(
              COMMAND,
              ARGS,
              MAXPROCS,
              info=INFO,
              root=self.ROOT,
          )
      else:
          child = self.COMM.Spawn_multiple(
              None,
              None,
              -1,
              info=MPI.INFO_NULL,
              root=self.ROOT,
          )
      child.Barrier()
      child.Disconnect()
      self.COMM.Barrier()
  
imports: from mpi4py import MPI
  import mpiunittest
  import sys, os, mpi4py
label_desc: Use image node_id 5 for calling the BaseTestSpawnMultiple obj's underlying member method code with example usage: obj.testArgsOnlyAtRoot() without return types