Iterator<Item> left = iterator();
                    Iterator<Item> right = ((ListItem) item).iterator();

                    while (left.hasNext() || right.hasNext()) {
                        Item l = left.hasNext() ? left.next() : null;
                        Item r = right.hasNext() ? right.next() : null;

                        // if this is shorter, then invert the compare and mul with -1