public virtual void test_other_Currency_same()
        {
            CurrencyPair test = CurrencyPair.of(GBP, GBP);

            assertEquals(test.other(GBP), GBP);
            assertThrows(typeof(System.ArgumentException), () => test.other(EUR));
        }
        public virtual void test_other_Currency_null()
        {
            CurrencyPair test = CurrencyPair.of(GBP, USD);

            assertThrowsIllegalArg(() => test.other(null));
        }