Flowables.kt

class Flowables private constructor(){
    companion object {
        inline fun <T, S> generateWith(noinline initialState: () -> S, crossinline generator: (S, Emitter<T>) -> S)
                = Flowable.generate(Callable<S>(initialState), BiFunction<S, Emitter<T>, S> { a, b -> generator.invoke(a, b) })
    }
}