@NonNull
    public Single<List<Item>> getItems() {
        return qualityMattersRestApi.items();
    }
Model is not an entity. It's a container for business logic code. M(VC), M(VP), M(VVM).
<p>
Why create Model classes? Such classes hide complex logic required to fetch/cache/process/etc data.
So Presentation layer won't know the details of implementation and each class will do only one job (SOLID).
app/src/main/java/com/artemzin/qualitymatters/models/ItemsModel.java