types.add(type);
  public void addType(GroupType type)     throws  GroupModifyException,            InsufficientPrivilegeException,            SchemaException  {    StopWatch sw = new StopWatch();    sw.start();    GroupValidator.canAddType(this.getSession(), this, type);    try {      Set types = this.getGroup_types();      this.setGroup_types(types);      HibernateGroupDAO.update(this);      sw.stop();      EventLog.info(        this.getSession(),        M.GROUP_ADDTYPE + U.q(this.getName()) + " type=" + U.q(type.toString()),        sw      );    }    catch (GrouperDAOException eDAO) {      String msg = E.GROUP_TYPEADD + type + ": " + eDAO.getMessage();      ErrorLog.error(Group.class, msg);      throw new GroupModifyException(msg, eDAO);     }  } // public void addType(type)