code: def setUp(self):
      super().setUp()
      if "TPU_API_DISCOVERY_URL" in os.environ:
          del os.environ["TPU_API_DISCOVERY_URL"]
      if "TPU_NAME" in os.environ:
          del os.environ["TPU_NAME"]
      self._time_now = 0
      self.addCleanup(mock.patch.stopall)
  
imports: import datetime
  import json
  import os
  import time
  import urllib
  from absl import flags
  from tensorflow.python.platform import test
  from tensorflow.python.tpu.client import client
label_desc: Use image node_id 1 for calling the CloudTpuClientTest obj's underlying member method code with example usage: obj.setUp() without return types