refresh method

@override Future<void> refresh({ bool notifyImmediately = true, })

Triggers notifyListeners after a zero-duration delay. Returns a Future that completes once the notify has been scheduled and (potentially) fired — callers that need to read post-notify state can await it.

Safe to call right before dispose; the scheduled tick is a no-op once isDisposed flips true.

Implementation

@override
Future<void> refresh({bool notifyImmediately = true}) {
  return _enqueue(() async {
    _sharedPreferences ??= await _getPrefs();
    final v = _sharedPreferences!.get(key);
    final newValue = fromValue(v is B ? v : null);
    _set(newValue, notifyImmediately: notifyImmediately);
  });
}