anchor.diff:    }
   
     void run(fn) {
  +    time = html.window.performance.now();
  +
       _zone.run(() {
         flags |= tickRunningFlag;
   
  
positive.code:   static const int runningFlags = tickRunningFlag | frameRunningFlag;
  
    int flags = 0;
    int clock = 1;
  
    bool get isRunning => ((flags & runningFlags) != 0);
    bool get isFrameRunning => ((flags & frameRunningFlag) != 0);
  
negative.code:   _WriteGroup _writeGroup;
  
    HeapPriorityQueue<_WriteGroup> _writeQueue =
    new HeapPriorityQueue<_WriteGroup>();
  
    Completer _readCompleter;
    Completer _afterCompleter;
  