`Maybe.subscribeWith()` [documentation ](https://github.com/ReactiveX/RxJava/blob/v2.1.5-RC4/src/main/java/io/reactivex/Maybe.java#L3771-L3799) suggests that it returns a `Disposable` and contains this example (translated to Kotlin): ```kotlin val source = Maybe.just(1) val composite = CompositeDisposable() val ms = object : MaybeObserver<Int> { // ... } composite.add(source.subscribeWith(ms)) ``` This code does not compile, because `MaybeObserver` does not implement `Disposable`. Should the documentation suggest to use `DisposableMaybeObserver` here? If yes, I can submit a PR.