anchor.diff:    bool _debugInheritLocked = false;
     bool _isNotifyDependentsEnabled = true;
     bool _firstBuild = true;
  -
  -  @override
  -  void mount(Element parent, dynamic slot) {
  -    super.mount(parent, slot);
  -    if (_didWatchFrameId == false) {
  -      _didWatchFrameId = true;
  -      assert(_frameId == 0);
  -      void Function(Duration) callback;
  -
  -      callback = (Duration _) {
  -        _frameId++;
  -        SchedulerBinding.instance.addPostFrameCallback(callback);
  -      };
  -      SchedulerBinding.instance.addPostFrameCallback(callback);
  -    }
  -  }
  +  bool _shouldClearSelectors = false;
  +  bool _shouldClearMutationScheduled = false;
   
     @override
     void updateDependencies(Element dependent, Object aspect) {
  
positive.code: typedef _SelectorAspect<T> = bool Function(T value);
  
  class _SelectorDependency<T> {
    _SelectorDependency(this.latestFrameId);
  
    int latestFrameId;
  
    List<_SelectorAspect<T>> selectors = [];
  }
  
  bool _didWatchFrameId = false;
  int _frameId = 0;
  bool _debugCanSelect = true;
  
  mixin _InheritedProviderScopeMixin<T> on InheritedElement implements InheritedContext<T> {
  
negative.code:     }
  
      if (aspect is _SelectorAspect<T>) {
        final selectorDependency = (dependencies ?? _SelectorDependency<T>()) as _SelectorDependency<T>;
        if (_shouldClearSelectors) {
          _shouldClearSelectors = false;
          selectorDependency.selectors.clear();
        }
        if (_shouldClearMutationScheduled == false) {
          _shouldClearMutationScheduled = true;
          SchedulerBinding.instance.addPostFrameCallback((_) {
            _shouldClearSelectors = true;
          });
        }
        selectorDependency.selectors.add(aspect);
        setDependencies(dependent, selectorDependency);
  