private static function initInternalItem(
        $product_reference,
        $name,
        $quantity,
        $unit_price,
        $tax_rate,
        $discount,
        $total_amount,
        $type,
        $discount_description = null
    ) {
        $cartItem = new Item();
        $cartItem->setProductReference($product_reference)
            ->setName($name)
            ->setType($type)
            ->setQuantity($quantity)
            ->setUnitPrice($unit_price)
            ->setTaxRate($tax_rate)
            ->setDiscount($discount)
            ->setTotalAmount($total_amount);

        if ($type == TypeItems::DISCOUNT) {
            $cartItem->setDiscountDescription($discount_description);
        }

        return $cartItem;
    }