public static ISubscription Subscribe <T>(this IPublisher <T> source, Action <T> onNext, Action <Exception> onError, Action onCompleted)
 {
     return((ISubscription)source.AsIObservable().Subscribe(onNext, onError, onCompleted));
 }
 public static ISubscription Subscribe <T>(this IPublisher <T> source, Action <T> onNext)
 {
     return((ISubscription)source.AsIObservable().Subscribe(onNext));
 }