code: def get_ref_favorites(self, project, repository_id=None, identity_id=None):
          
          route_values = {}
          if project is not None:
              route_values['project'] = self._serialize.url('project', project, 'str')
          query_parameters = {}
          if repository_id is not None:
              query_parameters['repositoryId'] = self._serialize.query('repository_id', repository_id, 'str')
          if identity_id is not None:
              query_parameters['identityId'] = self._serialize.query('identity_id', identity_id, 'str')
          response = self._send(http_method='GET',
                                location_id='876f70af-5792-485a-a1c7-d0a7b2f42bbb',
                                version='5.1-preview.1',
                                route_values=route_values,
                                query_parameters=query_parameters)
          return self._deserialize('[GitRefFavorite]', self._unwrap_collection(response))
docs: GetRefFavorites.
          [Preview API] Gets the refs favorites for a repo and an identity.
          :param str project: Project ID or project name
          :param str repository_id: The id of the repository.
          :param str identity_id: The id of the identity whose favorites are to be retrieved. If null, the requesting identity is used.
          :rtype: [GitRefFavorite]