protected static function isQuirkMode()
    {
        if (null === self::$quirkMode) {
            self::$quirkMode = version_compare(PHP_VERSION, '5.5.4', '<') 
                    && version_compare(PHP_VERSION, '5.5.0', '>') 
                    || version_compare(PHP_VERSION, '5.4.20', '<');
        }
        return self::$quirkMode;
    }