public void AddAndAccessItems()
    {
        BaseCollection <int> collection = new BaseCollection <int>();

        collection.Add(1);
        collection.Add(2);

        Assert.AreEqual(1, collection[0]);
        Assert.AreEqual(1, collection.ElementAt(0));
        Assert.AreEqual(2, collection[1]);
        Assert.AreEqual(2, collection.ElementAt(1));
    }