ByteSource slice = source.slice(offset, length);

    assertArrayEquals(expected, slice.read());
  }

  public void testCopyToStream_doesNotCloseThatStream() throws IOException {
    TestOutputStream out = new TestOutputStream(ByteStreams.nullOutputStream());
    assertFalse(out.closed());
    source.copyTo(out);
    assertFalse(out.closed());
  }

  public void testClosesOnErrors_copyingToByteSinkThatThrows() {

  }

  @Override
  public OutputStream openStream() throws IOException {
    outputStreamOpened = true;
    bytes.reset(); // truncate
    return new Out();
  }

  private final class Out extends TestOutputStream {

    Out() throws IOException {
      super(bytes, options);
    }

    @Override
    public void close() throws IOException {
      outputStreamClosed = true;
      super.close();
    }
  }

    ByteSource slice = source.slice(offset, length);

    assertArrayEquals(expected, slice.read());
  }

  public void testCopyToStream_doesNotCloseThatStream() throws IOException {
    TestOutputStream out = new TestOutputStream(ByteStreams.nullOutputStream());
    assertFalse(out.closed());
    source.copyTo(out);
    assertFalse(out.closed());
  }

  public void testClosesOnErrors_copyingToByteSinkThatThrows() {

  }

  @Override
  public OutputStream openStream() throws IOException {
    outputStreamOpened = true;
    bytes.reset(); // truncate
    return new Out();
  }

  private final class Out extends TestOutputStream {

    Out() throws IOException {
      super(bytes, options);
    }

    @Override
    public void close() throws IOException {
      outputStreamClosed = true;
      super.close();
    }
  }