@Override
 public Map convert(List value) {
   List<ValueSetItem> from = value;
   Map<String, Map<String, Object>> result = new LinkedHashMap<>();
   for (ValueSetItem valueSetItem : from) {
     result.put(valueSetItem.getId(), convertItemToMap(valueSetItem));
   }
   return result;
 }
 private Map<String, Object> convertItemToMap(ValueSetItem valueSetItem) {
   Map<String, Object> result = new LinkedHashMap<>();
   result.put("id", valueSetItem.getId());
   result.put("members", valueSetItem.getMembers());
   return result;
 }