class SecurityUtil {

  static boolean 
  isTGSPrincipal(KerberosPrincipal principal) {
    if (principal == null)
      return false;
    if (principal.getName().equals("krbtgt/" + principal.getRealm() + 
        "@" + principal.getRealm())) {
      return true;
    }
    return false;
  }

  protected  SecurityUtil();

}