PostRepository.kt

interface PostRepository {
    fun getFeeds(): Observable<PagedList<Post>>
}

class PostRepositoryImpl : PostRepository {

    override fun getFeeds(): Observable<PagedList<Post>> {
        val dataSource = PostPagingDataSourceFactory()
        val pagedListConfig = PagedList.Config.Builder()
            .setPageSize(10)
            .setPrefetchDistance(4)
            .build()
        return RxPagedListBuilder(dataSource, pagedListConfig)
            .setFetchScheduler(Schedulers.io())
            .setNotifyScheduler(AndroidSchedulers.mainThread())
            .buildObservable()
    }
}