protected function _getSortCol()
    {
        $aVisibleNames = $this->_getVisibleColNames();
        $iCol = \OxidEsales\Eshop\Core\Registry::getConfig()->getRequestParameter('sort');
        $iCol = $iCol ? (( int ) str_replace('_', '', $iCol)) : 0;
        $iCol = (!isset($aVisibleNames[$iCol])) ? 0 : $iCol;

        return $iCol;
    }