static function fetchNotificationList( $status = 1, $length = null, $offset = 0, $sorts = null )
    {
        $cond = array();
        if ( is_null( $status ) )
        {
            $cond = null;
        }
        else
        {
        $cond['status'] = $status;
        }
        $limit = array();
        if ( is_null( $length ) )
        {
            $limit = null;
        }
        else
        {
            $limit['offset'] = $offset;
            $limit['length'] = $length;
        }
        return eZPersistentObject::fetchObjectList( self::definition(), null, $cond, $sorts, $limit );
    }