def retried_task(self, user_id, argument, **kwargs):  # pylint: disable=unused-argument
    """
    A task using the UserTask framework which fails once and succeeds on the retry.
    """
    if self.request.retries == 0:
        try:
            raise Exception('Boom!')
        except Exception as exc:
            raise self.retry(exc=exc)
    return argument