def close(self):
        """
        Should be called before deleting this instance of the level.
        Not calling this method may result in corrupted worlds
        :return: None
        """
        if PocketLeveldbDatabase.holdDatabaseOpen:
            if self._world_db is not None:
                del self._world_db
                self._world_db = None

        Should be called before deleting this instance of the level.
        Not calling this method may result in corrupted worlds
        :return: None
        
pymclevel/leveldbpocket.py