Is there an idiomatic way to say "emit T if `Obser...

# rx

[locke]

Is there an idiomatic way to say "emit T if ObservableSource has not emitted within N seconds?"

I currently have:

observableSource
    .mergeWith(Observable.timer(TIMEOUT, TimeUnit.Seconds).map { Result.Failure }) 
    .subscribe { 
        ...
    }

But the problem here is this will always emit after the TIMEOUT. I thought about using switchOnNext but that doesn't really help me with whether observableSource has emitted or not.