code: def setUpClass(cls):
      super(__class__, cls).setUpClass()
      codecs = VideoFileDataset.get_available_codecs()
      if ".mp4" in codecs.values():
          fname = "endo.mp4"
          config = testing_data_config("videos", "endovis")
          cls.known_fps = 2.0
          cls.known_num_frames = 23
      elif ".avi" in codecs.values():
          fname = "ultrasound.avi"
          config = testing_data_config("videos", "ultrasound")
          cls.known_fps = 2.0
          cls.known_num_frames = 523
      else:
          cls.known_fps = None
          cls.known_num_frames = None
          cls.video_source = None
          return
      cls.video_source = os.path.join(
          os.path.dirname(__file__), "testing_data", fname
      )
      download_url_or_skip_test(
          url=config["url"],
          filepath=cls.video_source,
          hash_val=config.get("hash_val"),
          hash_type=config.get("hash_type", "sha256"),
      )
  
imports: from __future__ import annotations
  import os
  import unittest
  import torch
  import monai.transforms
  from monai.data.dataloader import DataLoader
  from monai.data.video_dataset import CameraDataset, VideoDataset, VideoFileDataset
  from monai.utils.module import optional_import
  from tests.utils import assert_allclose, download_url_or_skip_test, testing_data_config
label_desc: Use image node_id 1 for calling the TestVideoFileDataset obj's underlying member method code with example usage: obj.setUpClass(cls) without return types