public void Currencies_are_equal_when_abbreviations_are_equal()
{
Assert.That(Currency.EUR == Currency.EUR, Is.True, "EUR should be equal to EUR");
Assert.That(Currency.EUR.Equals(Currency.EUR), Is.True, "EUR should be equal to EUR");
Assert.That(Currency.EUR != Currency.USD, Is.True, "EUR should not be equal to USD");
Assert.That(Currency.EUR.Equals(Currency.USD), Is.False, "EUR should not be equal to USD");
Assert.That(Currency.EUR == null, Is.False, "EUR should not be equal to null");
Assert.That(null == Currency.EUR, Is.False, "EUR should not be equal to null");
}