private void Sort(List <string> actual, List <string> expected)
{
// arrange
var comparer = new AlphaNumAlgorithm(null);
// act
var watch = new Stopwatch();
watch.Start();
actual.Sort(comparer);
watch.Stop();
// assert
Assert.IsTrue(expected.SequenceEqual(actual));
Console.WriteLine($"Performance = {watch.ElapsedTicks}");
}