RxSample.kt

Observable.just("Hey")
    .subscribeOn(Schedulers.io())
    .map(String::length)
    .subscribeOn(Schedulers.computation())
    .observeOn(AndroidSchedulers.mainThread())
    .doOnSubscribe { doAction() }
    .flatMap {
        doAction()
        Observable.timer(1, TimeUnit.SECONDS)
            .subscribeOn(Schedulers.single())
            .doOnSubscribe { doAction() }
    }.subscribe {
        doAction()
    }