behevioralStructural_Order.kt

class InvalidOrderStateToCancel: RuntimeException()

class Order(val orderSpecification: OrderSpecification) {
    fun cancel() {
        if (!orderSpecification.isCancellable(this)) {
            throw InvalidOrderStateToCancel()
        }
        //…cancel order
    }

    fun isCancelled(): Boolean {
        //…check order status
        return true
    }
}

class OrderSpecification {
    fun isCancellable(order: Order): Boolean {
        //…check order status
        return true
    }
}