public PaymentService( IPaymentRepository paymentRepository, IPaymentValidator paymentValidator, IPaymentFactory paymentFactory) { paymentRepository.CheckArgumentIsNull(nameof(paymentRepository)); _paymentRepository = paymentRepository; paymentValidator.CheckArgumentIsNull(nameof(paymentValidator)); _paymentValidator = paymentValidator; paymentFactory.CheckArgumentIsNull(nameof(paymentFactory)); _paymentFactory = paymentFactory; }