template <class ItemType>
ArrayBag<ItemType> ArrayBag <ItemType> ::Union(const ArrayBag<ItemType> bag2)
{
    ArrayBag<ItemType> unionBag;

    for (int i = 0; i < getCurrentSize(); i++)
    {
        unionBag.add(items[i]);
    }

    for (int i = 0; i < bag2.getCurrentSize(); i++)
    {
        unionBag.add(bag2.items[i]);
        if (items[i] == bag2.items[i])
            unionBag.remove(bag2.items[i]);
    }

    return unionBag;
}