code: def assert_docker_file(self, expected_lines, docker_file):
      with open(docker_file, "r") as f:
          actual_lines = f.readlines()
          self.assertListEqual(expected_lines, actual_lines)
  
imports: import os
  import tempfile
  import uuid
  from absl.testing import absltest
  import docker
  import mock
  from tensorflow_cloud.core import containerize
  from tensorflow_cloud.core import docker_config
  from tensorflow_cloud.core import gcp
  from tensorflow_cloud.core import machine_config
  from tensorflow_cloud.utils import google_api_client
  from tensorflow_cloud.utils import tf_utils
label_desc: Use image node_id 3 for calling the TestContainerize obj's underlying member method code with example usage: obj.assert_docker_file(expected_lines, docker_file) without return types