restoreWithFuture method
USE WITH CARE. We're currently testing the new restore method
All In App purchases are handled async, it's difficult to work with futures.
We're waiting for the next purchase update and complete the future.
Implementation
Future<LinkFiveActiveProducts> restoreWithFuture() async {
makeSureIsInitialize();
final completer = Completer<LinkFiveActiveProducts>();
registeredPurchaseCompleterList.add(completer);
await restore();
return completer.future;
}