@asyncio.coroutine<EOL><INDENT>def respond(self, request, **kwargs):<DEDENT>
raise http.NotFound()<EOL>
Respond to a request (coroutine).

        Parameters
        ----------
        request: :class:`.http.Request`
            Request instance.
        kwargs: dict
            Keyword arguments.

        Returns
        -------
        object
            Reply value.