public function getVatInfo($isNettoMode = true)
    {
        $aVatValues = [];
        $aPrices = [];
        foreach ($this->_aList as $oPrice) {
            $sKey = ( string ) $oPrice->getVat();
            if (!isset($aPrices[$sKey])) {
                $aPrices[$sKey]['sum'] = 0;
                $aPrices[$sKey]['vat'] = $oPrice->getVat();
            }
            $aPrices[$sKey]['sum'] += $oPrice->getPrice();
        }

        foreach ($aPrices as $sKey => $aPrice) {
            if ($isNettoMode) {
                $dPrice = $aPrice['sum'] * $aPrice['vat'] / 100;
            } else {
                $dPrice = $aPrice['sum'] * $aPrice['vat'] / (100 + $aPrice['vat']);
            }
            $aVatValues[$sKey] = $dPrice;
        }

        return $aVatValues;
    }