code: def get_refresh_token_params(self, scope_list=None):
          
          if self.refresh_token is None:
              raise AttributeError('No refresh token is defined.')
  
          params = {
              'grant_type': 'refresh_token',
              'refresh_token': self.refresh_token,
          }
  
          if scope_list:
              if isinstance(scope_list, list):
                  scopes = '+'.join(scope_list)
              else:
                  raise AttributeError('scope_list must be a list of scope.')
              params['scope'] = scopes
  
          return self.__prepare_token_request(params)
docs: Return the param object for the post() call to get the access_token
          from the refresh_token
  
          :param code: the refresh token
          :return: a dict with the url, params and header