With the migration of MITK to ITK4, the method SurfaceToSurfaceFilter::RemoveInputs() has been removed. Reason for removal was probably that no code ever used it.
A branch from T15439 (3D surface interpolation) depends on this method, however. So we need to reimplement it based on ITK4. The actual code is simple and straight-forward. Will be required/tested by the implementation of T15439