TreeSet<String> allCategories = new TreeSet<String>();
TreeSet<Key> allCategories = new TreeSet<Key>();
	public void diffCounts(CountBugs newer) {		TreeSet<String> allCategories = new TreeSet<String>();		allCategories.addAll(countMap.keySet());		allCategories.addAll(newer.countMap.keySet());		for (Iterator<String> i = allCategories.iterator(); i.hasNext(); ) {			String category = i.next();			Integer delta = new Integer(newer.getCount(category).intValue() - getCount(category).intValue());			countMap.put(category, delta);		}	}