def _add_complete_key_entity_pb(self):
        # We use ``upsert`` for entities with completed keys, rather than
        # ``insert`` or ``update``, in order not to create race conditions
        # based on prior existence / removal of the entity.
        new_mutation = self.mutations.add()
        return new_mutation.upsert
Adds a new mutation for an entity with a completed key.
dataset/ETHPy150Open GoogleCloudPlatform/gcloud-python/gcloud/datastore/batch.py/Batch._add_complete_key_entity_pb