// save point
DBSavePoint point = connection.savePoint();
Author.cls.get(1).setLastName("test1");
connection.rollback(point);
connection.releasePoint(point);
connection.commit();
check( Author.cls.count() > 0 );
check( Library.cls.count() > 0 );
check( Book.cls.count() > 0 );
check( Member.cls.count() > 0 );
check( Transaction.cls.count() > 0 );