code: def testCountWorker(self):
      cluster_spec = {
          "chief": ["127.0.0.1:1234"],
          "worker": ["127.0.0.1:8964", "127.0.0.1:2333"],
          "ps": ["127.0.0.1:1926", "127.0.0.1:3141"],
      }
      self.assertEqual(
          multi_worker_util.worker_count(
              cluster_spec, task_type="chief"
          ),
          3,
      )
      self.assertEqual(
          multi_worker_util.worker_count(
              cluster_spec, task_type="worker"
          ),
          3,
      )
  
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 1 for calling the NumWorkersTest obj's underlying member method code with example usage: obj.testCountWorker() without return types