protected function listifyAttr($array) {
        ksort($array);
        $list = array();
        foreach ($array as $name => $obj) {
            if ($obj === false) continue;
            $list[] = "$name&nbsp;=&nbsp;<i>" . $this->getClass($obj, 'AttrDef_') . '</i>';
        }
        return $this->listify($list);
    }