protected Set getSet(JSONObject json, String propertyName, Class propertyElementType) {
JSONArray jsonArray = json.optJSONArray(propertyName);
if (jsonArray == null) {
return null;
}
Set set = new HashSet();
for (int i = 0; i < jsonArray.length(); i++) {
set.add(conversionService.fromJson(jsonArray.getJSONObject(i), propertyElementType));
}
return set;
}