anchor.diff:          });
         }
       }
  -    scheduleUpdatePosition();
  +    _updatePosition();
     }
   
     // A callback that sets up the animation from point a to point b.
     void _updatePosition() {
  -    _cardUpdateScheduled =
  -        false; // allow the next attempt to schedule _updatePosition to succeed.
       if (config.animationType == CardAnimationType.NONE ||
           _pointQueue.length == 1) {
         Point endingLocation = config.endingPosition;
  
positive.code:     }
    }
  
    // These microtasks are being scheduled on every build change.
    // Theoretically, this is too often, but to be safe, it is also good to do it.
    @override
    void didUpdateConfig(ZCard oldConfig) {
      if (config.key != oldConfig.key) {
  
negative.code:   List<
        Point> _pointQueue; // at least 1 longer than the current animation index.
    int _animationIndex;
  
    @override
    void initState() {
      super.initState();
      _initialize();
      _updatePosition();
    }
  
    void _initialize() {
  