PostListPage.kt

class PostListViewModel : ViewModel() {
    private val repo: PostRepository by inject()

    fun getNewPostList(): Observable<List<NewPost>> {
        return repo.getNewPostList()
    }
}

class PostListFragment : Fragment {
    private val viewModel by viewModel<PostListViewModel>()

    override fun onViewCreated() {
        viewModel.getNewPostList()
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe {
                // update list
            }
    }
}