out.write(chunk3);
    assertThat(source.read()).isEqualTo(concat(chunk1, chunk2, chunk3));

    out.reset();
  }


  public void testResetWhenGarbageCollected() throws Exception {
    FileAndWeakByteSource fileAndSource = leakFileBackedOutputStream();
    File file = fileAndSource.file;
    WeakReference<ByteSource> sourceRef = fileAndSource.sourceRef;