code: private static CmsUUID toUuid(String uuid) {
  
          if ("null".equals(uuid) || CmsStringUtil.isEmpty(uuid)) {
              return null;
          }
          return new CmsUUID(uuid);
  
      }
docs: Converts string to UUID and returns it, or null if the conversion is not possible.
  
  @param uuid the potential UUID string
  @return the UUID, or null if conversion is not possible