code: def add_url_rule(self, rule, endpoint=None, view_func=None, **options):
          
          self._defer(lambda app: app.add_url_rule(rule,
                                                   endpoint=endpoint,
                                                   view_func=view_func,
                                                   **options))
docs: Register a new url rule. Acts the same as :meth:`flask.Flask.add_url_rule`.