public function sortMultipleColumn($columns)
    {
        $compareFuncList = [];
        foreach($columns as $colName=>$asc) {
            $columnFormat = array_key_exists($colName, $this->dataFormats) ? $this->dataFormats[$colName] : Format::STRING;
            $compareFuncList[$colName] = $this->_getFunctionForFormat($columnFormat, $asc);
        }

        $this->uSortMultipleColumn($compareFuncList);
        return $this;
    }