code: private Iterator<IEntityGroup> getMemberGroups() throws GroupsException {
  
          Set<IEntityGroup> rslt = new HashSet<>();
          for (IGroupMember child : getChildren()) {
              if (child.isGroup()) {
                  rslt.add((IEntityGroup) child);
              }
          }
  
          return rslt.iterator();
      }
docs: Returns an <code>Iterator</code> over the groups in our member <code>Collection</code>.
  Reflects pending changes.
  
  @return Iterator