def reset(self, subject_id, entity_id):
        """ Scrap the assertions received from a IdP or an AA about a special
        subject.

        :param subject_id: The subjects identifier
        :param entity_id: The identifier of the entity_id of the assertion
        :return:
        """
        if not self._cache.set(_key(subject_id, entity_id), {}, 0):
            raise CacheError("reset failed")