* specific length.
   *
   * <p>For example, if you need 1024-bit hash codes, you could join two {@link Hashing#sha512} hash
   * functions together: {@code Hashing.concatenating(Hashing.sha512(), Hashing.sha512())}.
   *
   * @since 19.0
   */
  public static HashFunction concatenating(
      HashFunction first, HashFunction second, HashFunction... rest) {

 *
 * @author Kevin Bourrillion
 * @author Jesse Wilson
 * @author Austin Appleby
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class Hashing {
  private Hashing() {}

  /*
   * These should be ints, but we need to use longs to force GWT to do the multiplications with
   * enough precision.
   */
  private static final long C1 = 0xcc9e2d51;

 *
 * @author Kevin Bourrillion
 * @author Jesse Wilson
 * @author Austin Appleby
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class Hashing {
  private Hashing() {}

  /*
   * These should be ints, but we need to use longs to force GWT to do the multiplications with
   * enough precision.
   */
  private static final long C1 = 0xcc9e2d51;

    assertEquals(3, hashCodes.size());
  }

  public void testToString() {
    assertEquals("Hashing.sipHash24(" + K0 + ", " + K1 + ")", SIP_WITH_KEY.toString());
    assertEquals("Hashing.sipHash24(" + K0 + ", " + K1 + ")", SIP_WITHOUT_KEY.toString());
    assertEquals("Hashing.sipHash24(20, 13)", Hashing.sipHash24(20, 13).toString());
  }

  private static void assertSip(String input, long expected) {

 */
enum HashFunctionEnum {
  ADLER32(Hashing.adler32()),
  CRC32(Hashing.crc32()),
  GOOD_FAST_HASH_32(Hashing.goodFastHash(32)),
  GOOD_FAST_HASH_64(Hashing.goodFastHash(64)),
  GOOD_FAST_HASH_128(Hashing.goodFastHash(128)),
  GOOD_FAST_HASH_256(Hashing.goodFastHash(256)),
  MD5(Hashing.md5()),
  MURMUR3_128(Hashing.murmur3_128()),
  MURMUR3_32(Hashing.murmur3_32()),
  MURMUR3_32_FIXED(Hashing.murmur3_32_fixed()),
  SHA1(Hashing.sha1()),

    assertEquals("Hashing.md5()", Hashing.md5().toString());
    assertEquals("Hashing.sha1()", Hashing.sha1().toString());
    assertEquals("Hashing.sha256()", Hashing.sha256().toString());
    assertEquals("Hashing.sha512()", Hashing.sha512().toString());
  }

  private static void assertMessageDigestHashing(byte[] input, String algorithmName) {
    try {
      MessageDigest digest = MessageDigest.getInstance(algorithmName);

    assertEquals(
        "Hashing.hmacMd5(Key[algorithm=HmacMD5, format=RAW])", Hashing.hmacMd5(MD5_KEY).toString());
    assertEquals(
        "Hashing.hmacMd5(Key[algorithm=HmacMD5, format=RAW])", Hashing.hmacMd5(keyData).toString());

    assertEquals(
        "Hashing.hmacSha1(Key[algorithm=HmacSHA1, format=RAW])",
        Hashing.hmacSha1(SHA1_KEY).toString());
    assertEquals(

    verifyNoMoreInteractions(hashFunction, hasher);
  }

  public void testHash_hashesCorrectly() throws Exception {
    HashCode expectedHash = Hashing.md5().hashBytes(testBytes);
    HashingInputStream in = new HashingInputStream(Hashing.md5(), buffer);

    byte[] buf = new byte[4];
    int numOfByteRead = in.read(buf, 0, buf.length);
    assertEquals(4, numOfByteRead);

  }

  public void testHash_hashesCorrectly() throws Exception {
    byte[] buf = new byte[] {'y', 'a', 'm', 's'};
    HashCode expectedHash = Hashing.md5().hashBytes(buf);
    HashingOutputStream out = new HashingOutputStream(Hashing.md5(), buffer);

    out.write(buf);

    assertEquals(expectedHash, out.hash());
  }

  public void testChecksForNull() throws Exception {

    };
    ;

    public abstract byte[] hash(Algorithm algorithm, byte[] input);
  }

  private enum Algorithm {
    MD5("MD5", Hashing.md5()),
    SHA_1("SHA-1", Hashing.sha1()),
    SHA_256("SHA-256", Hashing.sha256()),
    SHA_384("SHA-384", Hashing.sha384()),
    SHA_512("SHA-512", Hashing.sha512());

    private final String algorithmName;
    private final HashFunction hashFn;