@Transactional
  public synchronized void removeGroup(Group group) throws AmbariException {
    final GroupEntity groupEntity = groupDAO.findByPK(group.getGroupId());
    if (groupEntity != null) {
      groupDAO.remove(groupEntity);
    } else {
      throw new AmbariException("Group " + group + " doesn't exist");
    }
  }
Gets all members of a group specified.

@param groupName group name
@return list of user names
ambari-server/src/main/java/org/apache/ambari/server/security/authorization/Users.java