code: @Override
      public SendTaskFailureResult sendTaskFailure(SendTaskFailureRequest request) {
          request = beforeClientExecution(request);
          return executeSendTaskFailure(request);
      }
docs: <p>
  Used by workers to report that the task identified by the <code>taskToken</code> failed.
  </p>
  
  @param sendTaskFailureRequest
  @return Result of the SendTaskFailure operation returned by the service.
  @throws TaskDoesNotExistException
  @throws InvalidTokenException
  The provided token is invalid.
  @throws TaskTimedOutException
  @sample AWSStepFunctions.SendTaskFailure
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/states-2016-11-23/SendTaskFailure" target="_top">AWS API
  Documentation</a>