def add(self, roles):
        """
        :param roles: _rolerepresentation array keycloak api
        """
        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)
        )
:param roles: _rolerepresentation array keycloak api