def combine(self, pathnames):
        """Combine predictions in waymo format for each sample together.
        Args:
            pathnames (str): Paths to save predictions.
        Returns:
            :obj:`Objects`: Combined predictions in Objects proto.
        """
        combined = metrics_pb2.Objects()

        for pathname in pathnames:
            objects = metrics_pb2.Objects()
            with open(pathname, 'rb') as f:
                objects.ParseFromString(f.read())
            for o in objects.objects:
                combined.objects.append(o)

        return combined
Combine predictions in waymo format for each sample together.
        Args:
            pathnames (str): Paths to save predictions.
        Returns:
            :obj:`Objects`: Combined predictions in Objects proto.
        
projects/mmdet3d_plugin/core/evaluation/kitti2waymo.py