code: def testErrcodes(self):
      self.COMM.Barrier()
      errcodes = []
      child = self.COMM.Spawn(
          self.COMMAND,
          self.ARGS,
          self.MAXPROCS,
          info=self.INFO,
          root=self.ROOT,
          errcodes=errcodes,
      )
      child.Barrier()
      child.Disconnect()
      self.COMM.Barrier()
      self.assertEqual(len(errcodes), self.MAXPROCS)
      for errcode in errcodes:
          self.assertEqual(errcode, MPI.SUCCESS)
  
imports: from mpi4py import MPI
  import mpiunittest
  import sys, os, mpi4py
label_desc: Use image node_id 2 for calling the BaseTestSpawnSingle obj's underlying member method code with example usage: obj.testErrcodes() without return types