code: def test_load_dataclass_dict_from_csv_throws(self):
      dataclass_objs = [
          TestDataclass2("a", 1),
          TestDataclass2("a", 2),
          TestDataclass2("b", 3),
          TestDataclass2("c", 4),
          TestDataclass2("c", 4),
          TestDataclass2("c", 4),
      ]
      with tempfile.TemporaryDirectory(
          prefix=f"{TestDataUtils}"
      ) as tempdir:
          csv_file_name = Path(tempdir) / "data.csv"
          save_dataclass_objs_to_headered_csv(
              dataclass_objs, csv_file_name
          )
          self.assertRaises(
              AssertionError,
              lambda: load_dataclass_dict_from_csv(
                  csv_file_name, TestDataclass2, "a", list_per_key=False
              ),
          )
  
imports: import os
  import tempfile
  import unittest
  import unittest.mock
  from dataclasses import dataclass
  from pathlib import Path
  from pytorchvideo.data.utils import DataclassFieldCaster, export_video_array, load_dataclass_dict_from_csv, save_dataclass_objs_to_headered_csv
  from pytorchvideo.data.video import VideoPathHandler
  from utils import temp_encoded_video
label_desc: Use image node_id 6 for calling the TestDataUtils obj's underlying member method code with example usage: obj.test_load_dataclass_dict_from_csv_throws() without return types