disposeForm not called

In the [video on integrating sign in](https://youtu.be/Y-JawJ4m6Fg?t=1327), shouldn’t the disposeForm() method be called? I’m debugging breakpoints and not seeing that generated method called. Maybe it happens automatically? I just noticed it because the TextEditControllers seem to “randomly” drop off and not pick up new values (in my integration of it) after awhile, switching between screens. But that may have something to do with the emulator and hot reload, as restarting fixes it - for a little while.

In any case, wondering if missing the dispose would cause a leak?

```
onModelReady: (model) => listenToFormUpdated(model),
onDispose: () => disposeForm(), // <--- MISSING??
```