/** @param level -1 to get items */ private void boundablesAtLevel(int level, AbstractNode top, Collection boundables) { Assert.isTrue(level > -2); if (top.getLevel() == level) { boundables.add(top); return; } for (Iterator i = top.getChildBoundables().iterator(); i.hasNext(); ) { Boundable boundable = (Boundable) i.next(); if (boundable instanceof AbstractNode) { boundablesAtLevel(level, (AbstractNode) boundable, boundables); } else { Assert.isTrue(boundable instanceof ItemBoundable); if (level == -1) { boundables.add(boundable); } } } return; }