code: private CmsUUID readOptionalUUID(JSONValue val) {
  
          String id = readOptionalString(val);
          if (null != id) {
              try {
                  CmsUUID uuid = CmsUUID.valueOf(id);
                  return uuid;
              } catch (@SuppressWarnings("unused") NumberFormatException e) {
                  // Do nothing, just return null
              }
          }
          return null;
      }
docs: Read an optional uuid stored as JSON string.
  @param val the JSON value to read the uuid from.
  @return the uuid, or <code>null</code> if the uuid can not be read.