anchor.diff:    ScheduledServer._(this._server, this.description);
   
     /// Creates a new server listening on an automatically-allocated port on
  -  /// localhost. [description] is used to refer to the server in debugging
  +  /// 127.0.0.1. [description] is used to refer to the server in debugging
     /// messages.
     factory ScheduledServer([String description]) {
       var id = _count++;
  
positive.code: 
      var scheduledServer;
      scheduledServer = new ScheduledServer._(schedule(() {
        return SafeHttpServer.bind("localhost", 0).then((server) {
          server.listen(scheduledServer._handleRequest,
              onError: (e) => currentSchedule.signalError(e));
          currentSchedule.onComplete.schedule(server.close);
  
negative.code:   Future<int> get port => _server.then((s) => s.port);
  
    /// The base URL of the server, including its port.
    Future<Uri> get url => port.then((p) => Uri.parse("http://127.0.0.1:$p"));
  
    /// Schedules [handler] to handle a request to the server with [method] and
    /// [path]. The schedule will wait until an HTTP request is received. If that
  