code: def testWorkerNotInCluster(self):
      cluster_spec = {
          "chief": ["127.0.0.1:1234"],
          "ps": ["127.0.0.1:1926", "127.0.0.1:3141"],
      }
      multi_worker_util._validate_cluster_spec(
          cluster_spec, "evaluator", 0
      )
      with self.assertRaisesRegex(
          ValueError, "`task_type` 'worker' not found in cluster_spec."
      ):
          multi_worker_util._validate_cluster_spec(
              cluster_spec, "worker", 0
          )
  
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 2 for calling the ClusterSpecValidationTest obj's underlying member method code with example usage: obj.testWorkerNotInCluster() without return types