ContactsViewModel-ConstructorWithParameters.kt

class ContactsViewModel(val getContactsUseCase: GetContactsUseCase, parameters: Parameters) : ViewModel() {
  private val contactsLiveData: LiveData<Contacts> by lazy {
    val liveData = MutableLiveData<Contacts>()
    getContactsUseCase.loadContacts(parameters) { liveData.value = it }
    return@lazy liveData
  }

  fun contacts(parameters: Parameters): LiveData<Contacts> = contactsLiveData
}

class ContactsViewModelFactory(val getContactsUseCase: GetContactsUseCase, val parameters: Parameters)
  : ViewModelProvider.Factory {
  override fun <T : ViewModel> create(modelClass: Class<T>): T {
    return ContactsViewModel(getContactsUseCase, parameters) as T
  }
}