docs: private void writeEndMark() throws IOException {
      intLEBuffer.putInt(0, 0);
      out.write(intLEBuffer.array());
      if (frameInfo.isEnabled(FLG.Bits.CONTENT_CHECKSUM)) {
        intLEBuffer.putInt(0, frameInfo.currentStreamHash());
        out.write(intLEBuffer.array());
      }
      frameInfo.finish();
    }