anchor.diff:    }
   
     // after a timeout, wait for an animation frame to actually run things
  -  run() => window.animationFrame.then((delta) => checker(this.target).then(done));
  +  run() =>
  +      window.animationFrame.then((delta) => checker(this.target).then(done));
   }
   
   Future<int> checker(String url) {
  
positive.code:     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) {
  
    }
  
    Stream get onComplete => done.stream;
  }
  
negative.code:     for (var val in status.values) {
        if (active == 200) {
          active = val;
        } else if (val == 0) {
          active = 500;
        } else if (val > active) {
          active = val;
        }
      }
  