code: def _delete_entity(self):
          
          if self._is_ndb():
              _NDB_KEY(self._model, self._key_name).delete()
          else:
              entity_key = db.Key.from_path(self._model.kind(), self._key_name)
              db.delete(entity_key)
docs: Delete entity from datastore.
  
          Attempts to delete using the key_name stored on the object, whether or
          not the given key is in the datastore.