nullobjectpattern-bad-usage-2.kt

class Task(
    val description: String,
    val assignedTo: AssignedTo
)

sealed class AssignedTo(val name: String) {
    object Nobody : AssignedTo("")
    class User(name: String) : AssignedTo(name)
}

fun main() {
    val buyMilk = Task("Buy milk", AssignedTo.Nobody)
    val writePost = Task("Write post", AssignedTo.User("le0nidas"))
    print(buyMilk, writePost)
    //  Task 'Buy milk' is assigned to
    //  Task 'Write post' is assigned to le0nidas
}

private fun print(vararg tasks: Task) {
    tasks.forEach { task ->
        println("Task '${task.description}' is assigned to ${task.assignedTo.name}")
    }
}