docs: private Set<IGroupMember> primGetAllMembers(Set<IGroupMember> rslt) throws GroupsException {
          for (IGroupMember gm : getChildren()) {
              rslt.add(gm);
              if (gm.isGroup()) {
                  ((EntityGroupImpl) gm).primGetAllMembers(rslt);
              }
          }
          return rslt;
      }