Hashing.hmacSha256(keyData).toString());

    assertEquals(
        "Hashing.hmacSha512(Key[algorithm=HmacSHA512, format=RAW])",
        Hashing.hmacSha512(SHA512_KEY).toString());
    assertEquals(
        "Hashing.hmacSha512(Key[algorithm=HmacSHA512, format=RAW])",
        Hashing.hmacSha512(keyData).toString());
  }

  private static void assertMacHashing(

   * @throws IllegalArgumentException if the given key is inappropriate for initializing this MAC
   * @since 20.0
   */
  public static HashFunction hmacSha512(Key key) {
    return new MacHashFunction("HmacSHA512", key, hmacToString("hmacSha512", key));
  }

  /**
   * Returns a hash function implementing the Message Authentication Code (MAC) algorithm, using the