public function getTotalValueForItemType($sType)
    {
        $dTotal = 0;
        reset($this->items);
        /** @var TPkgShopPaymentTransactionItemData $oItem */
        foreach ($this->items as $oItem) {
            if ($sType !== $oItem->getType()) {
                continue;
            }
            $dTotal = $dTotal + ($oItem->getAmount() * $oItem->getValue());
        }

        return $dTotal;
    }