* instance that is ready to receive data. Example:
   *
   * <pre>{@code
   * HashFunction hf = Hashing.md5();
   * HashCode hc = hf.newHasher()
   *     .putLong(id)
   *     .putBoolean(isActive)
   *     .hash();
   * }</pre>
   */
  Hasher newHasher();

  /**
   * Begins a new hash code computation as {@link #newHasher()}, but provides a hint of the expected

    sink.putInt(0x04030201);
    HashCode unused = sink.hash();
    sink.assertInvariants(4);
    sink.assertBytes(new byte[] {1, 2, 3, 4});
  }

  public void testLong() {
    Sink sink = new Sink(8);
    sink.putLong(0x0807060504030201L);
    HashCode unused = sink.hash();
    sink.assertInvariants(8);
    sink.assertBytes(new byte[] {1, 2, 3, 4, 5, 6, 7, 8});
  }

  public void testChar() {
    Sink sink = new Sink(4);

    PUT_LONG() {
      @Override
      void performAction(Random random, Iterable<? extends PrimitiveSink> sinks) {
        long value = random.nextLong();
        for (PrimitiveSink sink : sinks) {
          sink.putLong(value);
        }
      }
    },
    PUT_FLOAT() {
      @Override
      void performAction(Random random, Iterable<? extends PrimitiveSink> sinks) {
        float value = random.nextFloat();

    PUT_LONG() {
      @Override
      void performAction(Random random, Iterable<? extends PrimitiveSink> sinks) {
        long value = random.nextLong();
        for (PrimitiveSink sink : sinks) {
          sink.putLong(value);
        }
      }
    },
    PUT_FLOAT() {
      @Override
      void performAction(Random random, Iterable<? extends PrimitiveSink> sinks) {
        float value = random.nextFloat();

    hasher = HASH_FN.newHasher();
    hasher.putBytes(new byte[] {0x01, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00});
    assertEquals(hashCode, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();
    hasher.putLong(0x0000000001000101L);
    assertEquals(hashCode, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();
    hasher
        .putShort((short) 0x0101)
        .putShort((short) 0x0100)

    sink.putInt(0x04030201);
    HashCode unused = sink.hash();
    sink.assertInvariants(4);
    sink.assertBytes(new byte[] {1, 2, 3, 4});
  }

  public void testLong() {
    Sink sink = new Sink(8);
    sink.putLong(0x0807060504030201L);
    HashCode unused = sink.hash();
    sink.assertInvariants(8);
    sink.assertBytes(new byte[] {1, 2, 3, 4, 5, 6, 7, 8});
  }

  public void testChar() {
    Sink sink = new Sink(4);

    }

    @CanIgnoreReturnValue
    @Override
    public Hasher putInt(int i) {
      update(4, i);
      return this;
    }

    @CanIgnoreReturnValue
    @Override
    public Hasher putLong(long l) {
      update(4, (int) l);
      update(4, l >>> 32);
      return this;
    }

    @CanIgnoreReturnValue
    @Override
    public Hasher putChar(char c) {
      update(2, c);

  }

  private static final class CustomFunnel implements Funnel<Long> {
    @Override
    public void funnel(Long value, PrimitiveSink into) {
      into.putLong(value);
    }

    @Override
    public boolean equals(@Nullable Object object) {
      return (object instanceof CustomFunnel);
    }

    @Override
    public int hashCode() {
      return 42;

  }

  private static final class CustomFunnel implements Funnel<Long> {
    @Override
    public void funnel(Long value, PrimitiveSink into) {
      into.putLong(value);
    }

    @Override
    public boolean equals(@Nullable Object object) {
      return (object instanceof CustomFunnel);
    }

    @Override
    public int hashCode() {
      return 42;

    checkNotNull(buffer);
    checkArgument(
        buffer.remaining() >= BYTES,
        "Expected at least Stats.BYTES = %s remaining , got %s",
        BYTES,
        buffer.remaining());
    buffer
        .putLong(count)
        .putDouble(mean)
        .putDouble(sumOfSquaresOfDeltas)
        .putDouble(min)
        .putDouble(max);
  }

  /**