protected function _matchRelative($url) {
        $relative = $this->_relative();
        if (!$relative) {
            return true;
        }
        $components = parse_url($url);
        if (!isset($components['host'])) {
            return true;
        }
        $path = trim($components['path'], '/');
        return strpos($path, $relative) === 0;
    }