docs: protected static List<String> parseOptionalStringValues(JSONObject json, String key) {
  
          List<String> list = null;
          try {
              list = parseMandatoryStringValues(json, key);
          } catch (JSONException e) {
              LOG.info(Messages.get().getBundle().key(Messages.LOG_OPTIONAL_STRING_LIST_MISSING_1, key), e);
              return null;
          }
          return list;
      }