No, it has changed since the Rx course. It returns [Unit](https://github.com/Netflix/RxJava/blob/master/language-adaptors/rxjava-scala/src/main/scala/rx/lang/scala/Observable.scala#L2328). A [Subscriber](https://github.com/Netflix/RxJava/blob/master/language-adaptors/rxjava-scala/src/main/scala/rx/lang/scala/Subscriber.scala) is also a subscription now.

Oh. I forgot to link the subscriptions together (like it is done in SbtClientWithObservable).