Iterator itr = tiles.iterator();
Iterator itr = iterator();
    public int getTileHeightMax() {        int maxHeight = 0;        Iterator itr = tiles.iterator();        while (itr.hasNext()) {            Tile t = (Tile)itr.next();            if (t != null && t.getHeight() > maxHeight) {                maxHeight = t.getHeight();            }        }        return maxHeight;    }