BeerListViewModel.kt

class BeerListViewModel (private val beerRepository: BeerRepository): ViewModel(), CoroutineScope {

    private var job = Job()
    override val coroutineContext: CoroutineContext
        get() = Dispatchers.IO + job

    fun getBeers(): LiveData<List<BeerResponse>> {
        val beers = MutableLiveData<List<BeerResponse>>()

        launch {
            beers.postValue(beerRepository.getBeers())
        }

        return beers
    }

    fun onDestroy() {
        job.cancel()
    }
}

BeerRepository.kt

class BeerRepository @Inject constructor(private val beerDao: BeerDao,
                                         private val punkService: PunkService) {

    suspend fun getBeers(): List<BeerResponse>? {
        val response = punkService.getBeers().await()
        return response.body()
    }

    suspend fun getBeerById(beerId: Int): BeerResponse? {
        val response = punkService.getBeerById(beerId).await()
        return response.body()?.get(0)
    }

DetailViewModel.kt

class DetailViewModel (private val beerRepository: BeerRepository): ViewModel(), CoroutineScope {
    private var job = Job()
    override val coroutineContext: CoroutineContext
        get() = Dispatchers.IO + job

    fun getBeer(beerId: Int): LiveData<BeerResponse> {
        val beer = MutableLiveData<BeerResponse>()

        launch {
            beer.postValue(beerRepository.getBeerById(beerId))
        }

        return beer
    }

    fun onDestroy() {
        job.cancel()
    }
}