anchor.diff:  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> {
  
positive.code:     }
  
      if (aspect is _SelectorAspect<T>) {
        final selectorDependency = (dependencies ?? _SelectorDependency<T>(_frameId)) as _SelectorDependency<T>;
        if (selectorDependency.latestFrameId != _frameId) {
          selectorDependency.latestFrameId = _frameId;
          selectorDependency.selectors.clear();
        }
        selectorDependency.selectors.add(aspect);
        setDependencies(dependent, selectorDependency);
  
negative.code:   bool _debugInheritLocked = false;
    bool _isNotifyDependentsEnabled = true;
    bool _firstBuild = true;
    bool _shouldClearSelectors = false;
    bool _shouldClearMutationScheduled = false;
  
    @override
    void updateDependencies(Element dependent, Object aspect) {
  