docs: def load_cookies_file(cookies_file):
      """
      Load cookies file.
  
      We pre-pend the file with the special Netscape header because the cookie
      loader is very particular about this string.
      """
  
      logging.debug('Loading cookie file %s into memory.', cookies_file)
  
      cookies = StringIO()
      cookies.write('# Netscape HTTP Cookie File')
      cookies.write(open(cookies_file, 'rU').read())
      cookies.flush()
      cookies.seek(0)
      return cookies