code: def _generate_refresh_request_body(self):
          
          body = urllib.parse.urlencode({
              'grant_type': 'refresh_token',
              'client_id': self.client_id,
              'client_secret': self.client_secret,
              'refresh_token': self.refresh_token,
          })
          return body
docs: Generate the body that will be used in the refresh request.