code: def authorization_code(self, code, redirect_uri):
          
          return self._token_request(grant_type='authorization_code', code=code,
                                     redirect_uri=redirect_uri)
docs: Retrieve access token by `authorization_code` grant.
  
          https://tools.ietf.org/html/rfc6749#section-4.1.3
  
          :param str code: The authorization code received from the authorization
              server.
          :param str redirect_uri: the identical value of the "redirect_uri"
              parameter in the authorization request.
          :rtype: dict
          :return: Access token response