'Must be implemented to return an appropriate instance of `~.httputil.HTTPMessageDelegate`
that can serve the request.
Routing implementations may pass additional kwargs to extend the routing logic.
:arg httputil.HTTPServerRequest request: current HTTP request.
:arg kwargs: additional keyword arguments passed by routing implementation.
:returns: an instance of `~.httputil.HTTPMessageDelegate` that will be used to
process the request.'

def find_handler(self, request, **kwargs):

    raise NotImplementedError()
