code: def get_grades(self, login=None, promotion=None, **kwargs):
          
  
          _login = kwargs.get(
              'login',
              login or self._login
          )
          _promotion_id = kwargs.get('promotion', promotion)
          _grades_url = GRADES_URL.format(login=_login, promo_id=_promotion_id)
          return self._request_api(url=_grades_url).json()
docs: Get a user's grades on a single promotion based on his login.
  
          Either use the `login` param, or the client's login if unset.
          :return: JSON