public void Calculate_ShouldReturnCorrectAppId_WhenValidAumid(string aumid, string appId)
        {
            var result = AppIdCalculator.Calculate(aumid);

            Assert.Equal(appId, result);
        }
 public void Calculate_ShouldThrowArgumentException_WhenNullOrEmpty(string aumid)
 {
     Assert.Throws <ArgumentException>(() => AppIdCalculator.Calculate(aumid));
 }