@Override
  public boolean wasStreamClosed() {
    return byteSink.wasStreamClosed();
  }

  @Override
  public Writer openStream() throws IOException {
    // using TestByteSink's output stream to get option behavior, so flush to it on every write
    return new FilterWriter(new OutputStreamWriter(byteSink.openStream(), UTF_8)) {
      @Override
      public void write(int c) throws IOException {
        super.write(c);
        flush();

    CharSource reader =
        new CharSource() {
          @Override
          public Reader openStream() throws IOException {
            if (counter[0]++ != 0) {
              throw new IllegalStateException("More than one source open");
            }
            return new FilterReader(source.openStream()) {
              @Override
              public void close() throws IOException {
                super.close();

    CharSource reader =
        new CharSource() {
          @Override
          public Reader openStream() throws IOException {
            if (counter[0]++ != 0) {
              throw new IllegalStateException("More than one source open");
            }
            return new FilterReader(source.openStream()) {
              @Override
              public void close() throws IOException {
                super.close();

    ByteSource checker =
        new ByteSource() {
          @Override
          public InputStream openStream() throws IOException {
            if (counter[0]++ != 0) {
              throw new IllegalStateException("More than one source open");
            }
            return new FilterInputStream(source.openStream()) {
              @Override
              public void close() throws IOException {
                super.close();

    ByteSource checker =
        new ByteSource() {
          @Override
          public InputStream openStream() throws IOException {
            if (counter[0]++ != 0) {
              throw new IllegalStateException("More than one source open");
            }
            return new FilterInputStream(source.openStream()) {
              @Override
              public void close() throws IOException {
                super.close();

  }

  @Override
  public void setUp() throws IOException {
    source = factory.createSource(data);
  }

  public void testOpenStream() throws IOException {
    InputStream in = source.openStream();
    try {
      byte[] readBytes = ByteStreams.toByteArray(in);
      assertExpectedBytes(readBytes);
    } finally {
      in.close();
    }
  }

  }

  @Override
  public boolean wasStreamClosed() {
    return byteSource.wasStreamClosed();
  }

  @Override
  public Reader openStream() throws IOException {
    return new InputStreamReader(byteSource.openStream(), UTF_8);
  }

   */
  public abstract OutputStream openStream() throws IOException;

  /**
   * Opens a new buffered {@link OutputStream} for writing to this sink. The returned stream is not
   * required to be a {@link BufferedOutputStream} in order to allow implementations to simply
   * delegate to {@link #openStream()} when the stream returned by that method does not benefit from

   */
  public abstract InputStream openStream() throws IOException;

  /**
   * Opens a new buffered {@link InputStream} for reading from this source. The returned stream is
   * not required to be a {@link BufferedInputStream} in order to allow implementations to simply
   * delegate to {@link #openStream()} when the stream returned by that method does not benefit from

  @Override
  public boolean wasStreamClosed() {
    return byteSink.wasStreamClosed();
  }

  @Override
  public Writer openStream() throws IOException {
    // using TestByteSink's output stream to get option behavior, so flush to it on every write
    return new FilterWriter(new OutputStreamWriter(byteSink.openStream(), UTF_8)) {
      @Override
      public void write(int c) throws IOException {
        super.write(c);
        flush();