private function create404(Http\Request $request, Http\Response $response)
    {
        $response        = $response->withStatus(404);
        $originalRequest = $request->getOriginalRequest();
        $uri             = $originalRequest->getUri();
        $escaper         = new Escaper();
        $message         = sprintf(
            "Cannot %s %s\n",
            $escaper->escapeHtml($request->getMethod()),
            $escaper->escapeHtml((string) $uri)
        );
        return $response->end($message);
    }