Create RxObservable with timer

RxObservableTimer.swift

func createRxObservable() {
    let source: Observable<Int> = Observable<Int>.timer(3, scheduler: ConcurrentDispatchQueueScheduler.init(qos: DispatchQoS.background))
    
    source
        .subscribe(onNext: { number in
            print("Current emitted number: ", number)
        }, onError: { _ in print("On Error") },
           onCompleted: { print("Complete") },
           onDisposed: nil)
}