public static AwaitableAsyncSubject <TSource> GetAwaiter <TSource>(this IObservable <TSource> source)
        {
            var s = new AwaitableAsyncSubject <TSource>();

            source.SubscribeSafe(s);
            return(s);
        }
 public Subscription(AwaitableAsyncSubject <T> subject, IObserver <T> observer)
 {
     _subject  = subject;
     _observer = observer;
 }