docs: def token_urlsafe(nbytes=32):
      """Return a random URL-safe text string, in Base64 encoding.
  
      This is taken and slightly modified from the Python 3.6 stdlib.
  
      The string has *nbytes* random bytes.  If *nbytes* is ``None``
      or not supplied, a reasonable default is used.
  
      >>> token_urlsafe(16)  #doctest:+SKIP
      'Drmhze6EPcv0fN_81Bj-nA'
  
      """
      tok = os.urandom(nbytes)
      return base64.urlsafe_b64encode(tok).rstrip(b'=').decode('ascii')