code: def testGetEndpoint_FailWithoutStartingFirst(self):
      # Prepare mocks and variables.
      runner = self._create_local_docker_runner()
  
      # Act.
      with self.assertRaises(AssertionError):
          runner.GetEndpoint()
  
imports: import os
  from typing import Any, Dict
  from unittest import mock
  from docker import errors
  import tensorflow
  from tfx.components.infra_validator import error_types
  from tfx.components.infra_validator import serving_bins
  from tfx.components.infra_validator.model_server_runners import local_docker_runner
  from tfx.proto import infra_validator_pb2
  from tfx.types import standard_artifacts
  from tfx.utils import path_utils
  from google.protobuf import json_format
label_desc: Use image node_id 6 for calling the LocalDockerRunnerTest obj's underlying member method code with example usage: obj.testGetEndpoint_FailWithoutStartingFirst() without return types