text: # Copyright 2019 Google LLC. All Rights Reserved.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  """Definition of TFX runner base class."""
  
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  
  import abc
  from six import with_metaclass
  from typing import Any, Optional
  
  
  class TfxRunner(with_metaclass(abc.ABCMeta, object)):
    """Base runner class for TFX.
  
    This is the base class for every TFX runner.
  
    """
  
    @abc.abstractmethod
    def run(self, pipeline) -> Optional[Any]:
      """Runs logical TFX pipeline on specific platform.
  
      Args:
        pipeline: logical TFX pipeline definition.
  
      Returns:
        Platform-specific object.
      """
      pass
  