如果我尝试通过重写小部件dispose方法来更新stateProvider，我会得到一个异常，如下所示。知道如何更新状态，以便下次重建此小部件时使用null状态吗？
代码：

@override
void dispose() {
  //reset any request map initial bounds
  ref.read(fsdMapStateProvider.notifier).state = null;
  super.dispose();
}

错误：

════════ Exception caught by widgets library ═══════════════════════════════════
The following assertion was thrown while finalizing the widget tree:
Looking up a deactivated widget's ancestor is unsafe.

At this point the state of the widget's element tree is no longer stable.

To safely refer to a widget's ancestor in its dispose() method, save a reference to the ancestor by calling dependOnInheritedWidgetOfExactType() in the widget's didChangeDependencies() method.