public void WhenHaveCurrencyNull_ShouldHaveError()
        {
            var sut = new CarddtoValidator();

            sut.ShouldHaveValidationErrorFor(m => m.currency, null as string);
        }
        public void WhenCvvLessthan4Characters_ShouldHaveError()
        {
            var sut = new CarddtoValidator();

            sut.ShouldHaveValidationErrorFor(m => m.cvv, 123);
        }
        public void WhenCvvGreaterthanFourDigits_ShouldHaveError()
        {
            var sut = new CarddtoValidator();

            sut.ShouldHaveValidationErrorFor(m => m.cardnumber, 12345);
        }
        public void WhenCardNumberLessthan16Characters_ShouldHaveError()
        {
            var sut = new CarddtoValidator();

            sut.ShouldHaveValidationErrorFor(m => m.cardnumber, 123456);
        }