Dependency Rule: UseCase depends on the ViewModel

[darwingr]

The OutputBoundaries depend on their respective ViewModels.
As a result the UseCase component will also depend on the ViewModel, though it doesn't really need to.

What are some acceptable remedies here?
So far I see:

1. Change the return type of OutputBoundary#getViewModel() to the generic Object, use unit tests on the Presenter to satisfy doubts.
2. Add an empty ViewModelInterface for each UseCase component to be depended on by the OutputBoundary, UseCaseInteractor and the Controller while the Presenter uses the implementation directly.
3. Make a single empty ViewModel interface (set as immutable/sealed if possible) to be referred to in all the UseCase component. All ViewModels implement that interface and the rest is as above in # 2.