anchor.diff:      spinner = new DivElement()..classes.addAll(["spinner", "pie"]);
       filler = new DivElement()..classes.addAll(["filler", "pie"]);
       mask = new DivElement()..classes.add("mask");
  -    this.loader..append(spinner)..append(filler)..append(mask)..classes.add("loader");
  -  }
  -
  -  start(Duration dur) {
  -
  -  }
  +    this.loader
  +      ..append(spinner)
  +      ..append(filler)
  +      ..append(mask)
  +      ..classes.add("loader");
  +  }
  +
  +  start(Duration dur) {}
   
     Stream get onComplete => done.stream;
   }
  
positive.code: 
  String color(State s) {
    switch (s) {
      case State.GREEN: return "green";
      case State.YELLOW: return "yellow";
      case State.RED: return "red";
      default: return "gray";
    }
  }
  
  class Application {
    set state(State state) => _favicon.href = "$host/favicon.png?color=${color(state)}";
    final LinkElement _favicon = () {
      List<Node> links = document.getElementsByTagName("link");
      for (var link in links) if (link.attributes["rel"] == "icon") return link;
    }();
  
    Application() {
  
negative.code: 
    done(int status) {
      if (last != null) last.cancel();
      obj.classes.removeAll([
        'status-loading',
        'status-ignore',
        'status-ok',
        'status-warn',
        'status-bad'
      ]);
      if (200 <= status && status < 300) {
        obj.classes.add('status-ok');
      } else if (status == 429) {
  