public void Test()
{
SequenceList <int> list = new SequenceList <int>(5);
// 1, 2, 3, 4
list.Add(1);
list.Add(2);
list.Add(3);
list.Add(4);
Assert.Equal(4, list.Length);
Assert.Equal(2, list[1]);
// 1, 2, 3, 4
// 1, 2, 3, 5
list[3] = 5;
Assert.Equal(4, list.Length);
Assert.Equal(5, list[3]);
// 1, 2, 3, 5
// 1, 8, 2, 3, 5
list.Insert(1, 8);
Assert.Equal(5, list.Length);
Assert.Equal(8, list[1]);
Assert.Equal(2, list[2]);
// 1, 8, 2, 3, 5
// 1, 2, 3, 5
int removedItem = list.RemoveAt(1);
Assert.Equal(4, list.Length);
Assert.Equal(8, removedItem);
Assert.Equal(2, list[1]);
list.Clear();
Assert.Equal(0, list.Length);
}