def load_protobuf(dir):
        """
        Args:
            dir (str): a directory used to save Caffe2Model with
                :meth:`save_protobuf`.
                The files "model.pb" and "model_init.pb" are needed.

        Returns:
            Caffe2Model: the caffe2 model loaded from this directory.
        """
        predict_net = caffe2_pb2.NetDef()
        with PathManager.open(os.path.join(dir, "model.pb"), "rb") as f:
            predict_net.ParseFromString(f.read())

        init_net = caffe2_pb2.NetDef()
        with PathManager.open(os.path.join(dir, "model_init.pb"), "rb") as f:
            init_net.ParseFromString(f.read())

        return Caffe2Model(predict_net, init_net)

        Args:
            dir (str): a directory used to save Caffe2Model with
                :meth:`save_protobuf`.
                The files "model.pb" and "model_init.pb" are needed.

        Returns:
            Caffe2Model: the caffe2 model loaded from this directory.
        
video_chat_text/video_chat_with_MOSS/models/grit_src/third_party/CenterNet2/detectron2/export/api.py