public function restore($id)
    {
        $cart = $this->repo->findByIdAndInstanceName($id, $this->instanceName);

        if ($cart === null) {
            return;
        }

        $unserialized = unserialize(json_decode($cart->content));
        $this->content = $unserialized['content'];
        $this->coupons = $unserialized['coupons'];

        $this->instance($cart->instance);

        return $this;
    }