public interface IOrderService

{

    void ProcessOrder();

}

​

public interface IEmailService

{

    void SendEmail();

}

​

public class OrderService : IOrderService

{

    private readonly IEmailService _emailService;

​

    public OrderService(IEmailService emailService)

    {

        _emailService = emailService;

    }

​

    public void ProcessOrder()

    {

        // Order processing logic

        Console.WriteLine("Order processed.");

​

        _emailService.Value.SendEmail();

    }

}

​

public class EmailService : IEmailService

{

    private readonly IOrderService _orderService;

​

    public EmailService(IOrderService orderService)

    {

        _orderService = orderService;

    }

​

    public void SendEmail()

    {

        // Email sending logic

        Console.WriteLine("Email sent to customer.");

    }