public function run(ServerRequestInterface $request, ResponseInterface $response)
    {
        $route = $request->getAttribute('route');
        $callback = !empty($route->fn) ? $route->fn : null;

        if (!is_callable($callback)) {
            trigger_error("'fn' property of route shoud be a callable", E_USER_NOTICE);
            return $this->notFound($request, $response);
        }

        return $callback($request, $response);
    }