internal static T GetValueOrDefault <T>(this ValueSource <Optional <T> > optional, CancellationToken cancellationToken = default) where T : struct => optional.GetValue(cancellationToken).GetValueOrDefault();
internal static T?GetValueOrNull <T>(this ValueSource <Optional <T> > optional, CancellationToken cancellationToken = default) where T : class => optional.GetValue(cancellationToken).GetValueOrNull();