letstatement.java

getObservable()
            .filter { s -> someFilter(s) }
            .let{
                observable ->
                when(exteriorState){
                   STATE_1 -> observable.debounce(3, TimeUnit.SECONDS);
                   else -> observable.skip(3, TimeUnit.SECONDS)
                }
            }
            .subscribe{ v -> 
                //do on sub things
            }