public void Test2()
        {
            var window = new SlidingWindow <int>(2);
            var list1  = new List <int[]>();
            var list2  = new List <int[]>();

            var numbers = new[] { 11, 22, 33 };

            for (int i = 0; i < 3; i++)
            {
                window.Fill(numbers[i]);

                Assert.Equal(0 + 11 * i, window[0]);
                Assert.Equal(11 + 11 * i, window[1]);

                list1.Add(window.ToArray());
                list2.Add(window[0..2]);