finishedWhenPopped property Null safety
Controls whether didPop calls NavigatorState.finalizeRoute.
If true, this route removes its overlay entries during didPop. Subclasses can override this getter if they want to delay finalization (for example to animate the route's exit before removing it from the overlay).
Subclasses that return false from finishedWhenPopped are responsible for calling NavigatorState.finalizeRoute themselves.
@override bool get finishedWhenPopped => _controller!.status == AnimationStatus.dismissed && !_popFinalized;