lets_build_a_coroutine__state_object.kt

class State(
    var label: Int = 0,
    var result: Any? = null
)

fun saveUserTasks(userId: Int, state: State) {
    when (state.label) {
        0 -> {
            val user = loadUser(userId)
            println("user loaded")
            state.result = user
            //  pause execution
        }

        1 -> {
            //  resume execution
            val user = state.result as User
            val tasks = loadTasks(user)
            println("tasks loaded")
            state.result = tasks
            //  pause execution
        }

        2 -> {
            //  resume execution
            val tasks = state.result as List<Task>
            saveTasks(tasks)
        }
    }
}