public function getShippingTotal(): int
    {
        $shippingTotal = $this->getAdjustmentsTotal(AdjustmentInterface::SHIPPING_ADJUSTMENT);
        $shippingTotal += $this->getAdjustmentsTotal(AdjustmentInterface::ORDER_SHIPPING_PROMOTION_ADJUSTMENT);
        $shippingTotal += $this->getAdjustmentsTotal(AdjustmentInterface::TAX_ADJUSTMENT);

        return $shippingTotal;
    }