code: @Override
      public RetryStageExecutionResult retryStageExecution(RetryStageExecutionRequest request) {
          request = beforeClientExecution(request);
          return executeRetryStageExecution(request);
      }
docs: <p>
  Resumes the pipeline execution by retrying the last failed actions in a stage.
  </p>
  
  @param retryStageExecutionRequest
  Represents the input of a RetryStageExecution action.
  @return Result of the RetryStageExecution operation returned by the service.
  @throws ValidationException
  The validation was specified in an invalid format.
  @throws PipelineNotFoundException
  The specified pipeline was specified in an invalid format or cannot be found.
  @throws StageNotFoundException
  The specified stage was specified in an invalid format or cannot be found.
  @throws StageNotRetryableException
  The specified stage can't be retried because the pipeline structure or stage state changed after the
  stage was not completed; the stage contains no failed actions; one or more actions are still in progress;
  or another retry attempt is already in progress.
  @throws NotLatestPipelineExecutionException
  The stage has failed in a later run of the pipeline and the pipelineExecutionId associated with the
  request is out of date.
  @sample AWSCodePipeline.RetryStageExecution
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/codepipeline-2015-07-09/RetryStageExecution"
  target="_top">AWS API Documentation</a>