public static function traceEnd($res = '')
    {
        if (empty(self::$_PHPCAS_DEBUG['indent'])) {
            self::$_PHPCAS_DEBUG['indent'] = 0;
        } else {
            self::$_PHPCAS_DEBUG['indent']--;
        }
        $dbg = debug_backtrace();
        $str = '';
        if (is_object($res)) {
            $str .= '<= ' . get_class($res);
        } else {
            $str .= '<= ' . str_replace(array("\r\n", "\n", "\r"), "", var_export($res, true));
        }

        phpCAS :: log($str);
    }