`fetchReviews` is triggering the interactor that does fetching. When reviews are fetched, results are posted to `_reviews`.

I had an article about interactor ( use-case ), one I use here that fetches reviews is failry similar https://aksoymelih.medium.com/power-up-your-usecases-with-states-and-coroutines-in-android-44d3967f2a9f