code: def testGetSetDelete(self):
      INFO = self.INFO
      self.assertEqual(INFO.Get_nkeys(), 0)
      INFO.Set("key", "value")
      nkeys = INFO.Get_nkeys()
      self.assertEqual(nkeys, 1)
      key = INFO.Get_nthkey(0)
      self.assertEqual(key, "key")
      value = INFO.Get("key")
      self.assertEqual(value, "value")
      INFO.Delete("key")
      nkeys = INFO.Get_nkeys()
      self.assertEqual(nkeys, 0)
      value = INFO.Get("key")
      self.assertIsNone(value)
  
imports: from mpi4py import MPI
  import mpiunittest
  import sys
label_desc: Use image node_id 9 for calling the TestInfo obj's underlying member method code with example usage: obj.testGetSetDelete() without return types