WritableByteChannel outChannel = Channels.newChannel(out);

    File testFile = createTempFile();
    byte[] dummyData = newPreFilledByteArray(chunkSize);
    try (FileOutputStream fos = new FileOutputStream(testFile)) {
      for (int i = 0; i < 500; i++) {
        fos.write(dummyData);
      }
    }
    try (ReadableByteChannel inChannel = new RandomAccessFile(testFile, "r").getChannel()) {
      ByteStreams.copy(inChannel, outChannel);
    }

    WritableByteChannel outChannel = Channels.newChannel(out);

    File testFile = createTempFile();
    byte[] dummyData = newPreFilledByteArray(chunkSize);
    try (FileOutputStream fos = new FileOutputStream(testFile)) {
      for (int i = 0; i < 500; i++) {
        fos.write(dummyData);
      }
    }
    try (ReadableByteChannel inChannel = new RandomAccessFile(testFile, "r").getChannel()) {
      ByteStreams.copy(inChannel, outChannel);
    }