code: def add(self, roles):
          
          return self._client.post(
              url=self._client.get_full_url(
                  self.get_path(
                      'single', realm=self._realm_name, id=self._user_id
                  )
              ),
              data=json.dumps(roles, sort_keys=True)
          )
docs: :param roles: _rolerepresentation array keycloak api