code: public static String getUserNameFromCookieToken(String tokenStr) {
      Map<String, String> map = splitCookieToken(tokenStr);
  
      if (!map.keySet().equals(COOKIE_ATTRIBUTES)) {
        LOG.error("Invalid token with missing attributes " + tokenStr);
        return null;
      }
      return map.get(COOKIE_CLIENT_USER_NAME);
    }
docs: Parses a cookie token to retrieve client user name.
  @param tokenStr Token String.
  @return A valid user name if input is of valid format, else returns null.