initRun method
Implementation
@override
FutureOr<void> initRun(OverlayState state) async {
if (active) return;
assert(state.mounted);
_controller.init(overlayState: state, duration: duration);
if (delayDuration != Duration.zero) {
await release(delayDuration);
}
if (closed) return;
_controller.setObverser(_overlayObserver);
}