Obervable.create(emitter -> {
  emitter.onNext(1);
  emitter.onNext(2);
  emitter.onNext(3);
  // Thread.sleep(10);
  emitter.onError(new RuntimeException("error"));
}).subscribeOn(io())
.doOnEach(logger)
.observeOn(AndroidSchedulers.mainThread())
.doOnEach(logger)
.subscribe();