mainBugCollection = collection;
	public static BugSet loadBugsHelper(BugCollection collection)	{		ArrayList<BugLeafNode> bugList=new ArrayList<BugLeafNode>();		Iterator<BugInstance> i=collection.iterator();		while (i.hasNext())		{			bugList.add(new BugLeafNode(i.next()));		}				return new BugSet(bugList);			}