code: def _auth_with_refresh_token(session, refresh_token):
      
      # Make a token request.
      token_request_data = {
          'client_id': OAUTH2_CLIENT_ID,
          'client_secret': OAUTH2_CLIENT_SECRET,
          'grant_type': 'refresh_token',
          'refresh_token': refresh_token,
      }
      res = _make_token_request(session, token_request_data)
      return res['access_token']
docs: Authenticate using OAuth refresh token.
  
      Raises GoogleAuthError if authentication fails.
  
      Returns access token string.