restorationManager property Null safety

TestRestorationManager restorationManager
override

The RestorationManager synchronizes the restoration data between engine and framework.

See the docs for RestorationManager for a discussion of restoration state and how it is organized in Flutter.

To use a different RestorationManager subclasses can override createRestorationManager, which is called to create the instance returned by this getter.

Implementation

@override
TestRestorationManager get restorationManager {
  _restorationManager ??= createRestorationManager();
  return _restorationManager!;
}