code: def _test_save_load(self, verts, faces):
      with NamedTemporaryFile(mode="w", suffix=".obj") as f:
          file_path = Path(f.name)
          save_obj(file_path, verts, faces)
          f.flush()
  
          expected_verts, expected_faces = verts, faces
          if not len(
              expected_verts
          ):  # Always compare with a (V, 3) tensor
              expected_verts = torch.zeros(
                  size=(0, 3), dtype=torch.float32
              )
          if not len(
              expected_faces
          ):  # Always compare with an (F, 3) tensor
              expected_faces = torch.zeros(
                  size=(0, 3), dtype=torch.int64
              )
          actual_verts, actual_faces, _ = load_obj(file_path)
          self.assertClose(expected_verts, actual_verts)
          self.assertClose(expected_faces, actual_faces.verts_idx)
  
imports: import os
  import unittest
  import warnings
  from collections import Counter
  from io import StringIO
  from pathlib import Path
  from tempfile import NamedTemporaryFile, TemporaryDirectory
  import torch
  from iopath.common.file_io import PathManager
  from pytorch3d.io import IO, load_obj, load_objs_as_meshes, save_obj
  from pytorch3d.io.mtl_io import _bilinear_interpolation_grid_sample, _bilinear_interpolation_vectorized, _parse_mtl
  from pytorch3d.renderer import TexturesAtlas, TexturesUV, TexturesVertex
  from pytorch3d.structures import join_meshes_as_batch, Meshes
  from pytorch3d.utils import torus
  from .common_testing import get_pytorch3d_dir, get_tests_dir, load_rgb_image, TestCaseMixin
label_desc: Use image node_id 16 for calling the TestMeshObjIO obj's underlying member method code with example usage: obj._test_save_load(verts, faces) without return types