public function scopeCurrent($query)
    {
        $cart = $query->whereCurrent()->first();
        if (empty($cart)) {
            if (!Auth::guest()) {
                $cart = call_user_func( Config::get('shop.cart') . '::create', [
                    'user_id' =>  Auth::user()->shopId,
                    'session_id' =>  session('visitor_id')
                ]);
            } else {
                $cart = call_user_func( Config::get('shop.cart') . '::create', [
                    'session_id' =>  session('visitor_id')
                ]);
            }
        }

        return $cart;
    }