* https://github.com/google/guava/issues/3990
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class Java8Compatibility {
  static void clear(Buffer b) {
    b.clear();
  }

  static void flip(Buffer b) {
    b.flip();
  }

  static void limit(Buffer b, int limit) {
    b.limit(limit);
  }

@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class Java8Compatibility {
  static void clear(Buffer b) {
    b.clear();
  }

  static void flip(Buffer b) {
    b.flip();
  }

  static void limit(Buffer b, int limit) {
    b.limit(limit);
  }

  static void position(Buffer b, int position) {
    b.position(position);
  }

  private Java8Compatibility() {}

 * https://github.com/google/guava/issues/3990
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class Java8Compatibility {
  static void clear(Buffer b) {
    b.clear();
  }

  static void flip(Buffer b) {
    b.flip();
  }

  static void limit(Buffer b, int limit) {
    b.limit(limit);
  }

   */
  protected void processRemaining(ByteBuffer bb) {
    Java8Compatibility.position(bb, bb.limit()); // move at the end
    Java8Compatibility.limit(bb, chunkSize + 7); // get ready to pad with longs
    while (bb.position() < chunkSize) {
      bb.putLong(0);
    }
    Java8Compatibility.limit(bb, chunkSize);
    Java8Compatibility.flip(bb);
    process(bb);
  }

  @Override
  @CanIgnoreReturnValue

   */
  protected void processRemaining(ByteBuffer bb) {
    Java8Compatibility.position(bb, bb.limit()); // move at the end
    Java8Compatibility.limit(bb, chunkSize + 7); // get ready to pad with longs
    while (bb.position() < chunkSize) {
      bb.putLong(0);
    }
    Java8Compatibility.limit(bb, chunkSize);
    Java8Compatibility.flip(bb);
    process(bb);
  }

  @Override
  @CanIgnoreReturnValue

  private static CharBuffer grow(CharBuffer buf) {
    char[] copy = Arrays.copyOf(buf.array(), buf.capacity() * 2);
    CharBuffer bigger = CharBuffer.wrap(copy);
    Java8Compatibility.position(bigger, buf.position());
    Java8Compatibility.limit(bigger, buf.limit());
    return bigger;
  }

  /** Handle the case of underflow caused by needing more input characters. */
  private void readMoreChars() throws IOException {

  private static CharBuffer grow(CharBuffer buf) {
    char[] copy = Arrays.copyOf(buf.array(), buf.capacity() * 2);
    CharBuffer bigger = CharBuffer.wrap(copy);
    Java8Compatibility.position(bigger, buf.position());
    Java8Compatibility.limit(bigger, buf.limit());
    return bigger;
  }

  /** Handle the case of underflow caused by needing more input characters. */
  private void readMoreChars() throws IOException {

  }

  /** Updates this hasher with bytes from the given buffer. */
  protected void update(ByteBuffer b) {
    if (b.hasArray()) {
      update(b.array(), b.arrayOffset() + b.position(), b.remaining());
      Java8Compatibility.position(b, b.limit());
    } else {
      for (int remaining = b.remaining(); remaining > 0; remaining--) {
        update(b.get());
      }
    }
  }

    }

    checkNotNull(from);
    checkNotNull(to);
    long total = 0;
    CharBuffer buf = createBuffer();
    while (from.read(buf) != -1) {
      Java8Compatibility.flip(buf);
      to.append(buf);
      total += buf.remaining();
      Java8Compatibility.clear(buf);
    }
    return total;
  }

  // TODO(lukes): consider allowing callers to pass in a buffer to use, some callers would be able

  }

  /** Updates this hasher with bytes from the given buffer. */
  protected void update(ByteBuffer b) {
    if (b.hasArray()) {
      update(b.array(), b.arrayOffset() + b.position(), b.remaining());
      Java8Compatibility.position(b, b.limit());
    } else {
      for (int remaining = b.remaining(); remaining > 0; remaining--) {
        update(b.get());
      }
    }
  }