Sealed, not enumerated

Coming from Java, you may be tempted to overload your enum with functionality:

// Java code
enum PizzaOrderStatus {
    ORDER_RECEIVED, 
    PIZZA_BEING_MADE, 
    OUT_FOR_DELIVERY, 
    COMPLETED;


    public PizzaOrderStatus nextStatus() {
        switch (this) {
            case ORDER_RECEIVED: return PIZZA_BEING_MADE;
            case PIZZA_BEING_MADE: return OUT_FOR_DELIVERY;
            case OUT_FOR_DELIVERY: return COMPLETED;
            case COMPLETED:return COMPLETED;
        }
    }
}

Instead, you can use the sealed class:

sealed class PizzaOrderStatus(protected val orderId: Int) {
    abstract fun nextStatus() : PizzaOrderStatus
    class OrderReceived(orderId: Int) : PizzaOrderStatus(orderId) {
        override fun nextStatus(): PizzaOrderStatus {
            return PizzaBeingMade(orderId)
        }
    }

    class PizzaBeingMade(orderId: Int) : PizzaOrderStatus(orderId...