class_docstr: Test tf.data service cluster.
code: def start_workers(self):
      for worker in self.workers:
          worker.start()
  
imports: import os
  import shutil
  import tempfile
  from tensorflow.core.protobuf import service_config_pb2
  from tensorflow.python.data.experimental.ops import data_service_ops
  from tensorflow.python.data.experimental.service import server_lib
  from tensorflow.python.data.kernel_tests import test_base
  from tensorflow.python.data.ops import dataset_ops
  from tensorflow.python.framework import combinations
  from tensorflow.python.framework import dtypes
  from tensorflow.python.ops import math_ops
  from tensorflow.python.platform import googletest
label_desc: Use image node_id 5 for calling the TestCluster obj's underlying member method code with example usage: obj.start_workers() without return types