code: def testEnvironmentVarToNetworkEndpointsSingleGrpcAddress(self):
      self.assertEqual(
          [{"ipAddress": "1.2.3.4", "port": "2000"}],
          list(
              client._environment_var_to_network_endpoints(
                  "grpc://1.2.3.4:2000"
              )
          ),
      )
  
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 10 for calling the CloudTpuClientTest obj's underlying member method code with example usage: obj.testEnvironmentVarToNetworkEndpointsSingleGrpcAddress() without return types