code: def testLastUsedCode(self):
      lastuc = MPI.COMM_WORLD.Get_attr(MPI.LASTUSEDCODE)
      self.assertGreaterEqual(lastuc, 0)
  
imports: from mpi4py import MPI
  import mpiunittest
  import os
label_desc: Use image node_id 6 for calling the TestWorldAttrs obj's underlying member method code with example usage: obj.testLastUsedCode() without return types