public void Insert_Exception_IndexIsGreaterThanCount()
{
VirtualizingList<int> list = new VirtualizingList<int>();
list.UpdateCount(20);
Assert.ThrowsException<ArgumentOutOfRangeException>(() => list.Insert(21, 123));
}
public void Insert_InsertsItemIntoList()
{
VirtualizingList<int> list = new VirtualizingList<int>();
list.UpdateCount(20);
list[2] = 8;
list[10] = 42;
list.Insert(5, 123);
Assert.AreEqual(21, list.Count);
Assert.AreEqual(8, list[2]);
Assert.AreEqual(123, list[5]);
Assert.AreEqual(42, list[11]);
}