code: @GwtIncompatible("Unnecessary")
    private Writer streamToOutputWriter2(OutputStream stream) {
      if (outputCharset2 == null) {
        return new BufferedWriter(new OutputStreamWriter(stream, UTF_8));
      } else {
        return new BufferedWriter(
            new OutputStreamWriter(stream, outputCharset2));
      }
    }
docs: Create a writer with the newer output charset.