ViewStateDemo.kt

sealed class ViewState {
    object Loading: ViewState()
    class Success(val someData: String): ViewState()
    class Failure(val message: String): ViewState()
}

fun main() {
    val message = when (getViewState()) {
        is ViewState.Loading -> "Data is loading"
        is ViewState.Success -> "Got data: ${state.someData}"
        is ViewState.Failure -> "It failed! ${state.message}"
    }
    
    println(message)
}

fun getViewState(): ViewState = listOf(ViewState.Loading, ViewState.Success("MyData"), ViewState.Failure("Error")).random()