//interface for view/fragment/activity/whatever
interface LoginAcceptable {
    fun onChangeLocation()
    fun onLoginSuccess()
    fun onAppUpdateAvailable()
    fun renderLocationConfig(configuration: LocationConfiguration)
}

// typealias for livedata
typealias LoginEvent = LoginAcceptable.() -> Unit

// single livedata in viewModel
val ui = MutableLiveData<LoginEvent>()

// just syntax sugar
operator fun <T> MutableLiveData<T>.invoke(value: T) {
    postValue(value)
}


// somewhere in ViewModel
fun foo() {
     ui {
        onLoginSuccess()
        onChangeLocation()
    }
}