I need advice. branch/todo-mvp-clean. LongRunningUseCase

Suppose there is such [UseCase](https://github.com/westman2000/MVPCAndroid/blob/mvpc-loaders/app/src/main/java/corp/wmsoft/android/examples/mvpc/longrunning/iteractor/LongRunningUseCase.java)

And [Presenter](https://github.com/westman2000/MVPCAndroid/blob/mvpc-loaders/app/src/main/java/corp/wmsoft/android/examples/mvpc/longrunning/LongRunningPresenter.java) who using it.

When user start UseCase, i show loading, but because this is long running operation, user can close this screen(press back button, close activity), or even close application(press home button).
In this case, will be called detachView() and onDestroyed() ([presenter will be destroyed here](https://github.com/westman2000/MVPCAndroid/blob/mvpc-loaders/mvpcandroid/src/main/java/corp/wmsoft/android/lib/mvpc/presenter/loader/MVPCPresenterLoader.java))

But since the operation is continued in the background, presenter will receive
`onSuccess(LongRunningUseCase.ResponseValue response)`
but because view already detached, there will be Error.

And my questions are:
1. How to avoid this error? I understand i can just check if view is attached `isViewAttached()`. but maybe there is a more elegant solution? For example how I can unsubscribe from UseCase if presenter destroyed, and then callback will not be called?
2. I do not understand how and why there is a function call `onSuccess` in the presenter, if presenter was already destroyed in `MVPCPresenterLoader.onReset()`
3. Somebody thought to create an intermediate buffer(let's called ViewState) between the Presenter and View to save commands for the View. In case you Presenter was disconnected from the View, and background thread finish loading, we need to hide the ProgressBar and display data. But this commands must be send to View only after attachView... In generally i speak about somesing like [this](https://github.com/Arello-Mobile/Moxy/wiki)

Start by reading LongRunningUseCase.java, LongRunningPresenter.java, and MVPCPresenterLoader.java, focusing on detachView(), onDestroyed(), onReset(), and onSuccess(). Trace the lifecycle and callback path, then review the linked Moxy ViewState discussion. Done would require an agreed, documented lifecycle behavior for completion after the view or presenter is gone.

Written by the indexing model from the issue text.