@GuardedBy("this")
  private OutputStream out;

  @GuardedBy("this")
  @CheckForNull
  private MemoryOutput memory;

  @GuardedBy("this")
  @CheckForNull
  private File file;

  /** ByteArrayOutputStream that exposes its internals. */
  private static class MemoryOutput extends ByteArrayOutputStream {
    byte[] getBuffer() {
      return buf;
    }

    int getCount() {
      return count;

  @GuardedBy("this")
  private OutputStream out;

  @GuardedBy("this")
  @CheckForNull
  private MemoryOutput memory;

  @GuardedBy("this")
  @CheckForNull
  private File file;

  /** ByteArrayOutputStream that exposes its internals. */
  private static class MemoryOutput extends ByteArrayOutputStream {
    byte[] getBuffer() {
      return buf;
    }

    int getCount() {
      return count;