anchor.diff:  
     /// Returns an absolute URL for a given relative route path and parameters.
     String url(String routePath, {Route startingFrom, Map parameters}) {
  -    var baseRoute = startingFrom == null ? this.root : startingFrom;
  +    var baseRoute = startingFrom == null ? this.root : _dehandle(startingFrom);
       parameters = parameters == null ? {} : parameters;
       return (_useFragment ? '#' : '') +
           baseRoute._getHead(baseRoute._getTailUrl(routePath, parameters));
  +  }
  +
  +  Route _dehandle(Route r) {
  +    if (r is RouteHandle) {
  +      return r._getHost(r);
  +    }
  +    return r;
     }
   
     UrlMatch _getMatch(Route route, String path) {
  
positive.code:    */
    String reverse(String tail) {
      return path.reverse(parameters: _lastEvent.parameters, tail: tail);
    }
  }
  
  
negative.code:  */
  class Route {
    final String name;
    final Map<String, Route> _routes = new LinkedHashMap<String, Route>();
    final UrlMatcher path;
    final StreamController<RouteEvent> _onRouteController;
    final StreamController<RouteEvent> _onLeaveController;
  