public function getTotalCost() {
        $totalCost = $this->getCost();
        $adjustmentTotal = 0;

        foreach ($this->adjustments as $adjustment) {
            $adjustmentObject = Yii::createObject($adjustment);
            if($adjustmentObject instanceof CartSumAdjustment) {
                $adjustmentTotal += $adjustmentObject->countAdjustment($totalCost);
            }
        }

        return $totalCost + $adjustmentTotal;
    }