code: def testEvaluatorIsChief(self):
      cluster_spec = {
          "chief": ["127.0.0.1:1234"],
          "worker": ["127.0.0.1:8964", "127.0.0.1:2333"],
          "evaluator": ["127.0.0.1:2019"],
      }
      self.assertTrue(
          multi_worker_util.is_chief(cluster_spec, "evaluator", 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 3 for calling the IsChiefTest obj's underlying member method code with example usage: obj.testEvaluatorIsChief() without return types