code: def reset(self, subject_id, entity_id):
          
          if not self._cache.set(_key(subject_id, entity_id), {}, 0):
              raise CacheError("reset failed")
docs: 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: