protected function get_yui3lib_headcss() {
        global $CFG;

        $yuiformat = '-min';
        if ($this->yui3loader->filter === 'RAW') {
            $yuiformat = '';
        }

        $code = '';
        if ($this->yui3loader->combine) {
            if (!empty($this->yuicssmodules)) {
                $modules = array();
                foreach ($this->yuicssmodules as $module) {
                    $modules[] = "$CFG->yui3version/$module/$module-min.css";
                }
                $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->comboBase.implode('&amp;', $modules).'" />';
            }
            $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->local_comboBase.'rollup/'.$CFG->yui3version.'/yui-moodlesimple' . $yuiformat . '.css" />';

        } else {
            if (!empty($this->yuicssmodules)) {
                foreach ($this->yuicssmodules as $module) {
                    $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.$module.'/'.$module.'-min.css" />';
                }
            }
            $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->local_comboBase.'rollup/'.$CFG->yui3version.'/yui-moodlesimple' . $yuiformat . '.css" />';
        }

        if ($this->yui3loader->filter === 'RAW') {
            $code = str_replace('-min.css', '.css', $code);
        } else if ($this->yui3loader->filter === 'DEBUG') {
            $code = str_replace('-min.css', '.css', $code);
        }
        return $code;
    }