for medium article

viewmodel_resolver.kt

object ViewModelResolver {
    // step 1, we need a viewmodel which is creted by ViewmodelProviders 
    fun provideDetailViewModel():MovieDetailViewModel = ViewModelProviders
          .of(??, ??)
          .get(MovieDetailViewModel::class.java)

    // step 2, add dependencies of ViewmodelProviders, 
    // we have used added fragment Activty, so that we can support
    // multiple activities not just MovieDetail activity
    fun provideDetailViewModel(
            factory : MovieDetailViewModelFactory, 
            activity : FragmentActivity
    ) :MovieDetailViewModel = ViewModelProviders
            .of(activity, factory)
            .get(MovieDetailViewModel::class.java)
  
    // step 3, resolver for viewmodel factory?
    fun provideDetailViewModelFactory() = 
                MovieDetailViewModelFactory(??)
    
    // step 4, repository has already been resolved in App resolver
    fun provideDetailViewModelFactory(movieRepository : MovieRepository) 
        = MovieDetailViewModelFactory(movieRepository)
}