listenAppleIDSignInOnSuccess function Null safety

StreamSubscription<Event> listenAppleIDSignInOnSuccess(
  1. dynamic callback(
    1. Event
    )
)

Implementation

StreamSubscription<Event> listenAppleIDSignInOnSuccess(
    Function(Event) callback) {
  _subAppleIDSignInOnSuccess?.cancel();
  return _subAppleIDSignInOnSuccess =
      document.on['AppleIDSignInOnSuccess'].listen(callback);
}