public static function purge( $queryString = '' , $objectID = null, $languageCode = null )
    {
        // check that some conditions were passed
        if ( $queryString === '' and $objectID === null and $languageCode === null )
            return false;

        if ( $queryString !== '' )
            $conds['search_query'] = $queryString;

        if ( $objectID !== null )
            $conds['contentobject_id'] = $objectID;

        if ( $languageCode !== null )
            $conds['language_code'] = $languageCode;

        return parent::removeObject( self::definition(), $conds );
    }