code: def complete(self, GET):
          
          if 'error' in GET:
              raise OAuthError(
                  _("Received error while obtaining access token from %s: %s") % (
                      self.access_token_url, GET['error']))
          return self.get_access_token(code=GET.get('code'))
docs: Complete the OAuth2 flow by fetching an access token with the provided
          code in the GET parameters.