code: public void addRoleForGroup(String groupName, String roleName) {
          if (workgroups==null) {
              workgroups = new Workgroup[1];
              workgroups[0] = new Workgroup(null, groupName, null);
          }
          List<String> roles = workgroups[0].getRoles();
          if (roles==null) {
              roles = new ArrayList<String>();
              workgroups[0].setRoles(roles);
          }
          roles.add(roleName);
      }
docs: This is only used when UserVO is a member of UserGroupVO.
  Only that group is populated as a substructure to store roles.
  @param groupId
  @param roleName