DaggerInitial.kt

@Target(AnnotationTarget.FUNCTION)
@kotlin.annotation.Retention(AnnotationRetention.RUNTIME)
@MapKey
annotation class ViewModelKey(val value: KClass<out ViewModel>)

@Module
abstract class ViewModelModule {
    @Binds
    @IntoMap
    @ViewModelKey(MainViewModel::class)
    abstract fun providesMainViewModel(mainViewModel: MainViewModel): ViewModel
}

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

    @Suppress("UNCHECKED_CAST")
    override fun <T : ViewModel> create(modelClass: Class<T>): T {
        val provider = viewModels[modelClass]
        return if (provider != null) {
            provider.get() as T
        } else {
            throw IllegalArgumentException("Can't find provider for ViewModel class ${modelClass.simpleName}")
        }
    }
}