public static final GnizrDao getInstance(DataSource datasource){
if(gnizrDao == null){
gnizrDao = new GnizrDao();
gnizrDao.setBookmarkDao(new BookmarkDBDao(datasource));
gnizrDao.setUserDao(new UserDBDao(datasource));
gnizrDao.setLinkDao(new LinkDBDao(datasource));
gnizrDao.setTagDao(new TagDBDao(datasource));
gnizrDao.setFeedSubscriptionDao(new FeedSubscriptionDBDao(datasource));
gnizrDao.setForUserDao(new ForUserDBDao(datasource));
gnizrDao.setTagAssertionDao(new TagAssertionDBDao(datasource));
gnizrDao.setTagPropertyDao(new TagPropertyDBDao(datasource));