public Map listSets() throws OAIInternalServerError,
NoSetHierarchyException {
// throw new NoSetHierarchyException();
if (sets.size() == 0)
throw new NoSetHierarchyException();
Map listSetsMap = new LinkedHashMap();
listSetsMap.put("sets", sets.iterator());
return listSetsMap;
// ArrayList result = new ArrayList();
// Iterator i = sets.values().iterator();