.hash());
  }

  public void testCustomKey() throws Exception {
    SecretKey customKey =
        new SecretKey() {
          @Override
          public String getAlgorithm() {
            return "HmacMD5";
          }

          @Override
          public byte[] getEncoded() {
            return new byte[8];
          }

          @Override

  }

  private static String hmacToString(String methodName, Key key) {
    return "Hashing."
        + methodName
        + "(Key[algorithm="
        + key.getAlgorithm()
        + ", format="
        + key.getFormat()
        + "])";
  }

  /**
   * Returns a hash function implementing the CRC32C checksum algorithm (32 hash bits) as described