JAVA

		Observable.just(1, 2, 3, 4, 5)//
				.map(c -> {
					System.out.println("1 " + Thread.currentThread().getName());
					return c;
				})//
				.flatMap(a -> {

					return Observable.just(1) //
							.observeOn(Schedulers.io())//
							.map(b -> b)//
							.map(c -> {
								System.out.println("2 " +Thread.currentThread().getName());
								return c;
							});
				})//
				.map(c -> {
					System.out.println("3 " +Thread.currentThread().getName());
					return c;
				}) //
				.subscribe();


		while (true)
		{
		}