code: def _create_auth(team, timeout=None):
      
      url = get_registry_url(team)
      contents = _load_auth()
      auth = contents.get(url)
  
      if auth is not None:
          # If the access token expires within a minute, update it.
          if auth['expires_at'] < time.time() + 60:
              try:
                  auth = _update_auth(team, auth['refresh_token'], timeout)
              except CommandException as ex:
                  raise CommandException(
                      "Failed to update the access token (%s). Run `quilt login%s` again." %
                      (ex, ' ' + team if team else '')
                  )
              contents[url] = auth
              _save_auth(contents)
  
      return auth
docs: Reads the credentials, updates the access token if necessary, and returns it.