code: def setUp(self):
      # Note that test case fixtures are executed in both the main process and
      # worker processes.
      super().setUp()
      if combinations.in_main_process():
          combinations.env().tf_data_service_dispatcher = "localhost"
  
imports: import importlib
  import os
  import sys
  import unittest
  from absl.testing import parameterized
  from tensorflow.python.distribute import combinations
  from tensorflow.python.distribute import test_util
  from tensorflow.python.distribute.cluster_resolver import tfconfig_cluster_resolver
  from tensorflow.python.eager import context
  from tensorflow.python.framework import combinations
  from tensorflow.python.platform import test
label_desc: Use image node_id 1 for calling the ClusterCombinationTestEnvTest obj's underlying member method code with example usage: obj.setUp() without return types