Return a tuple with current processing status code and message.

def status(self, event):
        """Return a tuple with current processing status code and message."""
        result = AsyncResult(str(event.id))
        return (
            self.CELERY_STATES_TO_HTTP.get(result.state),
            result.info.get('message')
            if result.state in self.CELERY_RESULT_INFO_FOR and result.info
            else event.response.get('message')
        )