I need to have an indication in my `subscribe` tha...

# rx

[dimsuz]

I need to have an indication in my subscribe that the emitted item is the first one.
I tried to do this

Observable.combineLatest(
  Observable.just(true, false),
  Observable.just(SomeData(), SomeData(), SomeData(), ....).delay(3000), // emulates long running operation
  BiFunction { isFirst, data -> isFirst to data })
.subscribe({ (isFirst, data) -> println(isFirst) })

it prints false and never prints true - I guess this is because just emits all items way faster than second one catches up.
Note that second observable can emit many items, how many is unknown in advance