disposables.add(toObservableAndError(observableSuccess)
                // PART 6
                .doOnError {
                    e -> textView.text = getString(R.string.error_message).plus("\n\n" + e.message)
                }
                // PART 6.1
                .retryWhen {
                    Observables.zip(
                            it.map { it as? Exception ?: throw it },
                            Observable.interval(DELAY_BEFORE_RETRY.duration, DELAY_BEFORE_RETRY.timeUnit))
                            .map { if (it.second >= TIMEOUT.duration) throw it.first }
                }
                // Remember PART 4
                .filter { articleRemoteModel -> articleRemoteModel.createdAt.isBeforeNow }
                .map { articleRemoteModel -> ArticleMapper().remoteEntityToViewModel(articleRemoteModel) }
                .map { articleViewModel ->
                    articleViewModel.url + "\n\n" +
                            articleViewModel.title + "\n" +
                            articleViewModel.createdAt + "\n"
                }
                // Remember PART 5
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(
                        { formattedString -> textView.text = formattedString }
                ))