class ViewModelFactory @Inject constructor(private val viewModels: MutableMap<Class<out ViewModel>, Provider<ViewModel>>) : ViewModelProvider.Factory {

    override fun <T : ViewModel> create(modelClass: Class<T>): T {
        val viewModelProvider = viewModels[modelClass]
                ?: throw IllegalArgumentException("model class $modelClass not found")
        return viewModelProvider.get() as T
    }

}