public function parse(Request $request)
    {
        $route = $request->route();

        // Route may not be an instance of Illuminate\Routing\Route
        // (it's an array in Lumen <5.2) or not exist at all
        // (if the request was never dispatched)
        if (is_callable([$route, 'parameter'])) {
            return $route->parameter($this->key);
        }
    }