code: def unlink_rich_menu_from_user(self, user_id, timeout=None):
          
          self._delete(
              '/v2/bot/user/{user_id}/richmenu'.format(user_id=user_id),
              timeout=timeout
          )
docs: Call unlink rich menu from user API.
  
          https://developers.line.me/en/docs/messaging-api/reference/#unlink-rich-menu-from-user
  
          :param str user_id: ID of the user
          :param timeout: (optional) How long to wait for the server
              to send data before giving up, as a float,
              or a (connect timeout, read timeout) float tuple.
              Default is self.http_client.timeout
          :type timeout: float | tuple(float, float)