Returns the keys to be removed by `clear` in aggressive mode

        For the parameters, see BaseIndex.get_all_storage_keys

def get_all_storage_keys(self):
        """Returns the keys to be removed by `clear` in aggressive mode

        For the parameters, see BaseIndex.get_all_storage_keys
        """

        keys = set()
        for index in self._indexes:
            keys.update(index.get_all_storage_keys())

        return keys