public function add(array $product, array $data)
    {
        $result = array();
        $this->hook->attach('cart.add.product.before', $product, $data, $result, $this);

        if (!empty($result)) {
            return (array) $result;
        }

        $data += array(
            'quantity' => 1,
            'user_id' => $this->cart->getUid(),
            'store_id' => $product['store_id'],
            'product_id' => $product['product_id']
        );

        $data['cart_id'] = $this->set($data);

        if (empty($data['cart_id'])) {
            return $this->getResultError();
        }

        $result = $this->getResultAdded($data);
        $this->hook->attach('cart.add.product.after', $product, $data, $result, $this);
        return (array) $result;
    }