anchor.diff:    }
   
     void dispose() {
  -    _disposed = true;
  +    _pendingTaskCompleter?.complete();
  +    _pendingTaskCompleter = null;
     }
   }
  
positive.code:   }
  
    void _scheduleTask() {
      assert(!_disposed, 'tried to emit updates with a disposed Scheduler');
      if (_scheduledTask) return;
  
      _scheduledTask = true;
      assert(_pendingTaskCompleter == null, 'bad state');
      _pendingTaskCompleter = Completer<void>();
      vsync(_task);
    }
  
    void _task() {
      _pendingTaskCompleter!.complete();
      if (_disposed) return;
      _performRefresh();
      _performDispose();
  
      _scheduledTask = false;
      _stateToRefresh.clear();
      _stateToDispose.clear();
      _pendingTaskCompleter = null;
  
negative.code: 
    final void Function(void Function() onDone) vsync;
  
    final _stateToDispose = <AutoDisposeProviderElementBase>[];
    final _stateToRefresh = <ProviderElementBase>[];
  
  