code: def testDup(self):
      env = MPI.INFO_ENV
      dup = env.Dup()
      try:
          for key in self.KEYS:
              self.assertEqual(env.Get(key), dup.Get(key))
      finally:
          dup.Free()
  
imports: from mpi4py import MPI
  import mpiunittest
  import sys
label_desc: Use image node_id 4 for calling the TestInfoEnv obj's underlying member method code with example usage: obj.testDup() without return types