public KeyObserver(IKeyObservable <Key, T> source, Key key, Action <T> onNext)
{
this.source = source;
this.onNext = onNext;
this.subscription = this.source.Subscribe(key, this);
}
public SimpleKeyObserver(IKeyObservable <T, Key> source, Key key, Action <T> onNext)
{
this.source = source;
this.onNext = onNext;
this.subscription = this.source.Subscribe(this, key);
}