code: def testOverrideSimpleClusterResolver(self):
      base_cluster_spec = server_lib.ClusterSpec(
          {
              "ps": ["ps0:2222", "ps1:2222"],
              "worker": [
                  "worker0:2222",
                  "worker1:2222",
                  "worker2:2222",
              ],
          }
      )
  
      simple_resolver = cluster_resolver.SimpleClusterResolver(
          base_cluster_spec,
          task_type="ps",
          task_id=1,
          environment="cloud",
          num_accelerators={"GPU": 8},
          rpc_layer="grpc",
      )
  
      simple_resolver.task_type = "worker"
      simple_resolver.task_id = 2
      simple_resolver.rpc_layer = "http"
  
      self.assertEqual(simple_resolver.task_type, "worker")
      self.assertEqual(simple_resolver.task_id, 2)
      self.assertEqual(simple_resolver.rpc_layer, "http")
  
imports: from tensorflow.python.client import session
  from tensorflow.python.distribute.cluster_resolver import cluster_resolver
  from tensorflow.python.eager import context
  from tensorflow.python.framework import config
  from tensorflow.python.framework import test_util
  from tensorflow.python.platform import test
  from tensorflow.python.training import server_lib
label_desc: Use image node_id 4 for calling the UnionClusterResolverTest obj's underlying member method code with example usage: obj.testOverrideSimpleClusterResolver() without return types