protected function cacheResults($class, $method, $key, $closure)
    {
        $key = $class.'@'.$method.'.'.$key;

        if (method_exists(app()->make('cache')->getStore(), 'tags')) {
            return app()->make('cache')->tags($this->tag)->remember($key, 60, $closure);
        }

        return call_user_func($closure);
    }