code: def test_save_pretrained_basic(self):
      DummyModel().save_pretrained(self.cache_dir)
      files = os.listdir(self.cache_dir)
      self.assertTrue("pytorch_model.bin" in files)
      self.assertEqual(len(files), 1)
  
imports: import json
  import os
  import unittest
  from pathlib import Path
  from typing import TypeVar
  from unittest.mock import Mock, patch
  import pytest
  from huggingface_hub import HfApi, hf_hub_download
  from huggingface_hub.hub_mixin import PyTorchModelHubMixin
  from huggingface_hub.utils import SoftTemporaryDirectory, is_torch_available
  from .testing_constants import ENDPOINT_STAGING, TOKEN, USER
  from .testing_utils import repo_name
label_desc: Use image node_id 2 for calling the HubMixingTest obj's underlying member method code with example usage: obj.test_save_pretrained_basic() without return types