We already covered a few factories to create Observable sources, including Observable.create(), Observable.just(), and Observable.fromIterable(). After our detour covering Observers and their nuances, let's pick up where we left off and cover a few more Observable factories.
Other Observable sources
Observable.range()
To emit a consecutive range of integers, you can use Observable.range(). This will emit each number from a start value and increment each emission until the specified count is reached. These numbers are all passed through the onNext() event, followed by the  onComplete() event:
import io.reactivex.Observable;
public class Launcher {
public static void main(String[] args) {
Observable...