anchor.diff:              : useFragment;
   
     void addHandler(UrlPattern pattern, Handler handler) {
  +    _logger.finest('addHandler $pattern');
       _handlers[pattern] = handler;
     }
   
  
positive.code:    * with the path version of the URL by converting the # to a /.
     */
    void handle(String path) {
      var url = _getUrl(path);
      if (url != null) {
        // always give handlers a non-fragment path
  
negative.code: class Router {
    final Map<UrlPattern, Handler> _handlers;
    final bool useFragment;
    bool _listen = false;
  
    /**
     * [useFragment] determines whether this Router uses pure paths with
  