docs: def renew_close_to_expiration(self, margin_in_seconds=A_DAY):
          """Automatically renew subscriptions that are close to expiring, or
          have already expired. margin_in_seconds determines if a subscription is
          in fact close to expiring. By default, said margin is set to be a
          single day (24 hours).
  
          This is a long-running method for any non-trivial usage of the
          subscriber module, as renewal requires several http requests, and
          subscriptions are processed serially. Because of that, it is
          recommended to run this method in a celery task.
  
          """
          subscriptions = self.storage.close_to_expiration(margin_in_seconds)
          for subscription in subscriptions:
              try:
                  self.subscribe_impl(**subscription)
              except SubscriberError as e:
                  warn(RENEW_FAILURE % (subscription['topic_url'],
                                        subscription['callback_id']), e)