return position - oldPosition;
    }

    ByteBuffer buf = ByteBuffer.wrap(createBuffer());
    long total = 0;
    while (from.read(buf) != -1) {
      Java8Compatibility.flip(buf);
      while (buf.hasRemaining()) {
        total += to.write(buf);
      }
      Java8Compatibility.clear(buf);
    }
    return total;
  }

  /** Max array length on JVM. */

    byte[] bytes = new byte[rng.nextInt(256) + 1];
    rng.nextBytes(bytes);
    ByteBuffer buffer = ByteBuffer.wrap(bytes);
    HashCode unused = hashFunction.hashBytes(buffer);
    assertFalse(buffer.hasRemaining());
  }

  static void assertHashByteBufferPreservesByteOrder(HashFunction hashFunction) {
    Random rng = new Random(0L);
    byte[] bytes = new byte[rng.nextInt(256) + 1];
    rng.nextBytes(bytes);

      ByteOrder bo = buffer.order();
      buffer.order(ByteOrder.LITTLE_ENDIAN);
      while (buffer.remaining() >= 4) {
        putInt(buffer.getInt());
      }
      while (buffer.hasRemaining()) {
        putByte(buffer.get());
      }
      buffer.order(bo);
      return this;
    }

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

      if (finished) {
        return;
      }
      crc0 = combine(0, crc0);
      crc0 = combine(crc0, crc1);
      crc0 = combine(crc0, crc2);
      crc0 = combine(crc0, crc3);
      while (bb.hasRemaining()) {
        crc0 = (crc0 >>> 8) ^ BYTE_TABLE[(bb.get() ^ crc0) & 0xFF];
      }
      finished = true;
    }

    @Override
    protected HashCode makeHash() {
      if (!finished) {

    byte[] bytes = new byte[rng.nextInt(256) + 1];
    rng.nextBytes(bytes);
    ByteBuffer buffer = ByteBuffer.wrap(bytes);
    HashCode unused = hashFunction.hashBytes(buffer);
    assertFalse(buffer.hasRemaining());
  }

  static void assertHashByteBufferPreservesByteOrder(HashFunction hashFunction) {
    Random rng = new Random(0L);
    byte[] bytes = new byte[rng.nextInt(256) + 1];
    rng.nextBytes(bytes);