code: def testEnvironmentGCEDefault(self):
      self.assertEqual(
          "http://metadata.google.internal",
          client._gce_metadata_endpoint(),
      )
  
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 6 for calling the CloudTpuClientTest obj's underlying member method code with example usage: obj.testEnvironmentGCEDefault() without return types