static List[] cleanUnUsedGroupInstance( List[] groups )
public static List[] cleanUnUsedGroupInstance( List[] groups )
	static List[] cleanUnUsedGroupInstance( List[] groups )	{		List[] savedList = groups;		groups = new List[groups.length];		for(int i=0;i<groups.length;i++)		{			groups[i] = new ArrayList();		}		copy(savedList, groups);				int last = groups.length - 1;		List lastGroup = groups[last];		for( int i = 0; i < lastGroup.size(); i++ )		{			if( ((GroupInfo)lastGroup.get(i)).firstChild == -2 )			{				return cleanUnUsedGroupInstance( removeWholeGroup( groups, last, i));			}		}				copy( groups, savedList );		return savedList;	}