Odd question here. Why does this work? ``` privat...

# rx

[locke]

Odd question here. Why does this work?

private val filterSubject: BehaviorSubject<List<Int>> = BehaviorSubject.create<List<Int>>()

val observable: Observable<List<Int>>
        get() = filterSubject.map {
            it -> it.filter(filter)
        }

But this does not:

private val filterSubject: BehaviorSubject<List<Int>> = BehaviorSubject.create<List<Int>>().apply {
        map {
            it -> it.filter(filter)
        }
    }

val observable: Observable<List<Int>>
        get() = filterSubject