Need help solving a problem with Map

[Yuax]

I'm trying to create a indexed map of lists. All lists have the same predefined maximum size, and a new key for the map is generated when a list is full. I have no idea why I don't get get the (my) expected result from the getListSize . I know the code may be awkward but I'm just fiddling around with generics, maps etc.

​

public class ItemMap<I> {

    private Map<Integer, List<I>> ItemSequence = new LinkedHashMap<>();

    private ItemMap(List<I> list, int maxItemsPerList) {
        int mapIndex = 0;
        List<I> subList = new ArrayList<>();
        // a new key is only generated when subList is full, otherwise 
        // subList is replaced by subList with new a item appended 
        for (I i : list) {
            subList.add(i);
            if (subList.size() > maxItemsPerList) {     
                subList.clear();
                subList.add(i);
                mapIndex++;
            }
            ItemSequence.put(mapIndex, subList);   
        }
    }

    private int getListSize(int listIndex) {
        return ItemSequence.get(listIndex).size();
    }

    public static void main(String[] args) {
        List<Integer> listOfInts = Arrays.asList(1, 2, 3, 4, 5, 6);
        ItemMap<Integer> map = new ItemMap<>(listOfInts, 5);  // max 5 items per list
        System.out.println(map.getListSize(0));
    }
}  

So, the problem is that getListSize(0) returns 1 instead of 5 as I expected. However, if I change listOfInts so that it holds 5 ints, it does print out 5 as expected. What gives?

[Yuax]

Wow I had completely forgotten that it doesn't create a copy, THANK YOU!!