mac.init(SHA1_KEY);
    assertEquals(knownOutput, HashCode.fromBytes(mac.doFinal()).toString());
    assertEquals(knownOutput, Hashing.hmacMd5(SHA1_KEY).newHasher().hash().toString());
  }

  public void testKnownInputs() throws Exception {
    String knownOutput = "9753980fe94daa8ecaa82216519393a9";
    String input = "The quick brown fox jumps over the lazy dog";

    Mac mac = Mac.getInstance("HmacMD5");
    mac.init(MD5_KEY);