DDD (领域驱动设计)-用例可以返回实体实例吗？

class Order
{
    private $id;
    private $items;
    private $totalAmount;

    public function __construct($id, $items, $totalAmount)
    {
        $this->id = $id;
        $this->items = $items;
        $this->totalAmount = $totalAmount;
    }

    // 领域逻辑方法
    public function addItem($item)
    {
        $this->items[] = $item;
        $this->totalAmount += $item->price;
    }

    // Getter方法
    public function getId()
    {
        return $this->id;
    }

    public function getItems()
    {
        return $this->items;
    }

    public function getTotalAmount()
    {
        return $this->totalAmount;
    }
}

class CreateOrderUseCase
{
    private $orderRepository;

    public function __construct(OrderRepository $orderRepository)
    {
        $this->orderRepository = $orderRepository;
    }

    public function execute($orderData)
    {
        // 创建订单实体
        $order = new Order($orderData['id'], $orderData['items'], $orderData['totalAmount']);

        // 保存订单
        $this->orderRepository->save($order);

        // 返回DTO而不是实体
        return new OrderDTO($order->getId(), $order->getItems(), $order->getTotalAmount());
    }
}

class OrderDTO
{
    public $id;
    public $items;
    public $totalAmount;

    public function __construct($id, $items, $totalAmount)
    {
        $this->id = $id;
        $this->items = $items;
        $this->totalAmount = $totalAmount;
    }
}