repository.sessions
    .toResult(schedulerProvider)
    .toLiveData()

fun <T> Publisher<T>.toLiveData() = LiveDataReactiveStreams.fromPublisher(this)

data class SpeakerItem(
        val speaker: Speaker
) : BindableItem<ItemSpeakerBinding>(speaker.id.hashCode().toLong()) {

    override fun bind(viewBinding: ItemSpeakerBinding, position: Int) {
        viewBinding.speaker = speaker
    }

    override fun getLayout(): Int = R.layout.item_speaker
}

class SessionsFragment : Fragment(), Injectable {

    private lateinit var sessionsViewModel: SessionsViewModel

...
    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        ...
        lifecycle.addObserver(sessionsViewModel)
        ...

class SessionsViewModel @Inject constructor(
        private val repository: SessionRepository,
        private val schedulerProvider: SchedulerProvider
) : ViewModel(), LifecycleObserver {
  ...
    @OnLifecycleEvent(Lifecycle.Event.ON_CREATE)
    fun onCreate() {
    ...
}

    private val compositeDisposable: CompositeDisposable = CompositeDisposable()

    @OnLifecycleEvent(Lifecycle.Event.ON_CREATE)
    fun onCreate() {
        repository
                .refreshSessions()
                .subscribeBy(onError = defaultErrorHandler())
                .addTo(compositeDisposable)
    }

    override fun onCleared() {
        super.onCleared()
        compositeDisposable.clear()
    }

    override fun refreshSessions(): Completable {
        return api.getSessions()
                .doOnSuccess { response ->
                    sessionDatabase.save(response)
                }
                .subscribeOn(schedulerProvider.computation())
                .toCompletable()
    }

    @Query("SELECT room_id, room_name FROM session GROUP BY room_id ORDER BY room_id")
    abstract fun getAllRoom(): Flowable<List<RoomEntity>>

class SessionDataRepository @Inject constructor(
        private val sessionDatabase: SessionDatabase,
...
) : SessionRepository {

    override val rooms: Flowable<List<Room>> =
            sessionDatabase.getAllRoom().toRooms()

    val rooms: LiveData<Result<List<Room>>> by lazy {
        repository.rooms
                .toResult(schedulerProvider)
                .toLiveData()
    }

fun <T> Publisher<T>.toLiveData() = LiveDataReactiveStreams.fromPublisher(this) as LiveData<T>

fun <T> Flowable<T>.toResult(schedulerProvider: SchedulerProvider): Flowable<Result<T>> =
        compose { item ->
            item
                    .map { Result.success(it) }
                    .onErrorReturn { e -> Result.failure(e.message ?: "unknown", e) }
                    .observeOn(schedulerProvider.ui())
                    .startWith(Result.inProgress())
        }

sealed class Result<T>(val inProgress: Boolean) {
    class InProgress<T> : Result<T>(true)
    data class Success<T>(var data: T) : Result<T>(false)
    data class Failure<T>(val errorMessage: String?, val e: Throwable) : Result<T>(false)

        sessionsViewModel.rooms.observe(this, { result ->
            when (result) {
                is Result.InProgress -> {
                    binding.progress.show()
                }
                is Result.Success -> {
                    binding.progress.hide()
                    sessionsViewPagerAdapter.setRooms(result.data)
                }
                is Result.Failure -> {
                    Timber.e(result.e)
                    binding.progress.hide()
                }
            }
        })