protected function get_sort_direction(?int $sortmethod) : string {
        switch ($sortmethod) {
            case self::SORTORDER_LASTPOST_ASC:
            case self::SORTORDER_CREATED_ASC:
            case self::SORTORDER_REPLIES_ASC:
                return "ASC";
            case self::SORTORDER_LASTPOST_DESC:
            case self::SORTORDER_CREATED_DESC:
            case self::SORTORDER_REPLIES_DESC:
                return "DESC";
            default:
                return "DESC";
        }
    }