ef download_requests_stream(request_stream, destination, message=None):
    """This is a facility to download a request with nice progress bars."""
    if not message:
        message = 'Downloading {!r}'.format(os.path.basename(destination))

    total_length = int(request_stream.headers.get('Content-Length', '0'))
    if total_length:
        progress_bar = ProgressBar(
            widgets=[message,
                     Bar(marker='=', left='[', right=']'),
                     ' ', Percentage()],
            maxval=total_length)
    else:
        progress_bar = ProgressBar(
            widgets=[message, AnimatedMarker()],
            maxval=UnknownLength)

    total_read = 0
    progress_bar.start()
    with open(destination, 'wb') as destination_file:
        for buf in request_stream.iter_content(1024):
            destination_file.write(buf)
            total_read += len(buf)
            progress_bar.update(total_read)
    progress_bar.finish()