public void throw_an_exception_when_doesnt_have_any_coin()
 {
     Assert.Throws <ArgumentException>(() => CoinChanger.GetChange(1, new int[] { }));
 }
 public void throw_an_exception_when_coin_denomanitation_not_initialized()
 {
     Assert.Throws <ArgumentException>(() => CoinChanger.GetChange(1, null));
 }
        public void return_coin_change(int input, int[] coinDenomination, int[] expected)
        {
            int[] result = CoinChanger.GetChange(input, coinDenomination);

            Assert.AreEqual(expected, result);
        }