public void EncryptCard_ShouldEncryptACreditCard() { Card card = new Card { Number = creditCardNumber, SecurityCode = securityCode }; encryptionService.EncryptCard(card); Assert.That(card.Number, Is.Not.EqualTo(creditCardNumber)); Assert.That(card.SecurityCode, Is.Not.EqualTo(securityCode)); encryptionService.DecryptCard(card); Assert.That(card.Number, Is.EqualTo(creditCardNumber)); Assert.That(card.SecurityCode, Is.EqualTo(securityCode)); }