sealed_classes.kt

sealed class ScreenState3 {
    object LoadingState : ScreenState3()
    class ErrorState(val error: Throwable) : ScreenState3()
    class SuccessState(val data: String) : ScreenState3()
}

fun main(args: Array<String>) {

    val response3: ScreenState3 = ScreenState3.SuccessState("yay")

    when (response3) {
        is ScreenState3.SuccessState -> doStuff(response3.data)
        is ScreenState3.LoadingState -> { }
        is ScreenState3.ErrorState -> { }
    }
}

fun doStuff(data: String) {
    //NO-OP
}