SubscribeOnExample1.kt

fun debugSubscribeOn(): Disposable =
  Observable.just(1, 2, 3)
    .doOnNext {
      println(Thread.currentThread().name) // RxCachedThreadScheduler-1
    }
    .subscribeOn(Schedulers.io())
    .doOnNext {
      println(Thread.currentThread().name) // RxCachedThreadScheduler-1
    }
    .subscribe()