code: private static String getHttpOnlyCookieHeader(Cookie cookie) {
      NewCookie newCookie = new NewCookie(cookie.getName(), cookie.getValue(),
        cookie.getPath(), cookie.getDomain(), cookie.getVersion(),
        cookie.getComment(), cookie.getMaxAge(), cookie.getSecure());
      return newCookie + "; HttpOnly";
    }
docs: Generate httponly cookie from HS2 cookie
  @param cookie HS2 generated cookie
  @return The httponly cookie