code: def testUnexpectedInput(self):
      cluster_spec = ["127.0.0.1:8964", "127.0.0.1:2333"]
  
      with self.assertRaisesRegex(
          ValueError,
          "`cluster_spec' should be dict or a `tf.train.ClusterSpec` or a "
          "`tf.train.ClusterDef` object",
      ):
          multi_worker_util.normalize_cluster_spec(cluster_spec)
  
imports: from tensorflow.core.protobuf import cluster_pb2
  from tensorflow.python.distribute import multi_worker_util
  from tensorflow.python.eager import test
  from tensorflow.python.training import server_lib
label_desc: Use image node_id 5 for calling the NormalizeClusterSpecTest obj's underlying member method code with example usage: obj.testUnexpectedInput() without return types