code: def _threaded_copy_data(instream, outstream):
      
      copy_thread = threading.Thread(target=_copy_data,
                                     args=(instream, outstream))
      copy_thread.setDaemon(True)
      log.debug('%r, %r, %r', copy_thread, instream, outstream)
      copy_thread.start()
      return copy_thread
docs: Copy data from one stream to another in a separate thread.
  
      Wraps ``_copy_data()`` in a :class:`threading.Thread`.
  
      :type instream: :class:`io.BytesIO` or :class:`io.StringIO`
      :param instream: A byte stream to read from.
      :param file outstream: The file descriptor of a tmpfile to write to.