testJavaHMAC(
            "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
            Hex.decode("dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"),
            "56be34521d144c88dbb8c733f0e8b3f6");
    }


    private static void testJavaHMAC ( String key, String data, String expect ) throws GeneralSecurityException {