def __get__(self, model_instance, model_class):
    """Fetches collection of model instances of this collection property."""
    if model_instance is None:
      query = Query(self.__model)
      return query.filter(self.__property + ' =', model_instance.key())
    else:
      return self
dataset/ETHPy150Open CollabQ/CollabQ/.google_appengine/google/appengine/ext/db/__init__.py/_ReverseReferenceProperty.__get__/operator `is not` -> `is`