public void TestHexToBinConvrter_ConvertFails()
        {
            var c = new HexToBinConvertService();

            Assert.Throws <FormatException>(() => c.Convert("invalid hex"));
        }
        public void TestHexToBinConvrter_Converts(string input, string expected)
        {
            var c = new HexToBinConvertService();

            Assert.Equal(c.Convert(input), expected);
        }