<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def add_resource(self, resource, *urls, **kwargs):
 """Adds a resource to the api. :param resource: the class name of your resource :type resource: :class:`Type[Resource]` :param urls: one or more url routes to match for the resource, standard flask routing rules apply. Any url variables will be passed to the resource method as args. :type urls: str :param endpoint: endpoint name (defaults to :meth:`Resource.__name__.lower` Can be used to reference this route in :class:`fields.Url` fields :type endpoint: str :param resource_class_args: args to be forwarded to the constructor of the resource. :type resource_class_args: tuple :param resource_class_kwargs: kwargs to be forwarded to the constructor of the resource. :type resource_class_kwargs: dict Additional keyword arguments not specified above will be passed as-is to :meth:`flask.Flask.add_url_rule`. Examples:: api.add_resource(HelloWorld, '/', '/hello') api.add_resource(Foo, '/foo', endpoint="foo") api.add_resource(FooSpecial, '/special/foo', endpoint="foo") """

        if self.app is not None:
            self._register_view(self.app, resource, *urls, **kwargs)
        else:
            self.resources.append((resource, urls, kwargs))