*/
@Beta
@ElementTypesAreNonnullByDefault
public interface Hasher extends PrimitiveSink {
  @CanIgnoreReturnValue
  @Override
  Hasher putByte(byte b);

  @CanIgnoreReturnValue
  @Override
  Hasher putBytes(byte[] bytes);

  @CanIgnoreReturnValue
  @Override
  Hasher putBytes(byte[] bytes, int off, int len);

  @CanIgnoreReturnValue
  @Override
  Hasher putBytes(ByteBuffer bytes);

  @CanIgnoreReturnValue

  public void testPutAfterHash() {
    Hasher hasher = Hashing.hmacMd5(MD5_KEY).newHasher();

    assertEquals(
        "9753980fe94daa8ecaa82216519393a9",
        hasher.putString("The quick brown fox jumps over the lazy dog", UTF_8).hash().toString());
    assertThrows(IllegalStateException.class, () -> hasher.putInt(42));
  }

  public void testHashTwice() {
    Hasher hasher = Hashing.hmacMd5(MD5_KEY).newHasher();

      for (String algorithmToTest : ALGORITHMS.keySet()) {
        assertMessageDigestHashing(HashTestUtils.ascii(stringToTest), algorithmToTest);
      }
    }
  }

  public void testPutAfterHash() {
    Hasher sha1 = Hashing.sha1().newHasher();

    assertEquals(
        "2fd4e1c67a2d28fced849ee1bb76e7391b93eb12",
        sha1.putString("The quick brown fox jumps over the lazy dog", Charsets.UTF_8)
            .hash()

   *
   * @throws IOException if an I/O error occurs while reading from this source
   */
  public HashCode hash(HashFunction hashFunction) throws IOException {
    Hasher hasher = hashFunction.newHasher();
    copyTo(Funnels.asOutputStream(hasher));
    return hasher.hash();
  }

  /**
   * Checks that the contents of this byte source are equal to the contents of the given byte
   * source.
   *

  public void testPutAfterHash() {
    Hasher hasher = Hashing.hmacMd5(MD5_KEY).newHasher();

    assertEquals(
        "9753980fe94daa8ecaa82216519393a9",
        hasher.putString("The quick brown fox jumps over the lazy dog", UTF_8).hash().toString());
    assertThrows(IllegalStateException.class, () -> hasher.putInt(42));
  }

  public void testHashTwice() {
    Hasher hasher = Hashing.hmacMd5(MD5_KEY).newHasher();

            function.bits(),
            function);
      }
    }

    @Override
    HashCode makeHash(Hasher[] hashers) {
      byte[] bytes = new byte[bits() / 8];
      int i = 0;
      for (Hasher hasher : hashers) {
        HashCode newHash = hasher.hash();
        i += newHash.writeBytesTo(bytes, i, newHash.bits() / 8);
      }
      return HashCode.fromBytesNoCopy(bytes);
    }

    hasher.putShort((short) 0x0201);
    hasher.assertBytes(new byte[] {1, 2});
  }

  public void testInt() {
    TestHasher hasher = new TestHasher();
    hasher.putInt(0x04030201);
    hasher.assertBytes(new byte[] {1, 2, 3, 4});
  }

  public void testLong() {
    TestHasher hasher = new TestHasher();
    hasher.putLong(0x0807060504030201L);
    hasher.assertBytes(new byte[] {1, 2, 3, 4, 5, 6, 7, 8});

  private final ByteBuffer scratch = ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN);

  /** Updates this hasher with the given byte. */
  protected abstract void update(byte b);

  /** Updates this hasher with the given bytes. */
  protected void update(byte[] b) {
    update(b, 0, b.length);
  }

  /** Updates this hasher with {@code len} bytes starting at {@code off} in the given buffer. */

  @Override
  @CanIgnoreReturnValue
  public final Hasher putByte(byte b) {
    buffer.put(b);
    munchIfFull();
    return this;
  }

  @Override
  @CanIgnoreReturnValue
  public final Hasher putShort(short s) {
    buffer.putShort(s);
    munchIfFull();
    return this;
  }

  @Override
  @CanIgnoreReturnValue
  public final Hasher putChar(char c) {
    buffer.putChar(c);

      }
      // We need to ensure that at least 4 bytes have been put into the hasher or else
      // Hasher#hash will throw an ISE.
      int intToPut = random.nextInt();
      for (Hasher hasher : sinksAndControl) {
        hasher.putInt(intToPut);
      }
      for (Sink sink : sinks) {
        HashCode unused = sink.hash();
      }