public void MutateUnderlyingList(int initialCount)
        {
            List <int> original = new List <int>();

            for (int i = 0; i < initialCount; i++)
            {
                original.Add(i);
            }

            ReadOnlyCollection <int> wrapper = ListUtility.AsReadOnly(original);

            CollectionAssert.AreEqual(original, wrapper);

            original.Add(original.Count);
            CollectionAssert.AreEqual(original, wrapper);
        }