interface ViewModelState : Parcelable {
    val text: ObservableString
    val counter: ObservableInt
}

@Parcelize
data class ViewModelStateImpl(
        override val text: ObservableString = ObservableString(),
        override val counter: ObservableInt = ObservableInt()
) : ViewModelState

class ViewModel(val state: ViewModelState) : ViewModelState by state {

    init {
        counter.observe()
                .setTo(text) { "Wow! You count till $it" }
                .doOnNext { Log.d("THREAD", Thread.currentThread().name) }
                .subscribe()
    }

    fun incCounter() = counter.inc(10)
    fun decCounter() = counter.dec(0)

}