code: def test_recognition_uniform_clip_sampler(self):
      total_duration = 0.05
      with mock_json_annotations() as (
          annotation_json,
          labels,
          duration,
      ):
          clip_sampler = make_clip_sampler("uniform", total_duration)
          dataset = json_dataset.clip_recognition_dataset(
              data_path=annotation_json,
              clip_sampler=clip_sampler,
              decode_audio=False,
          )
  
          self.assertEqual(dataset.num_videos, 4)
          self.assertEqual(len(list(iter(dataset))), 4)
  
file_path: pytorchvideo/tests/test_data_json_dataset.py
imports: import contextlib
  import json
  import tempfile
  import unittest
  from pytorchvideo.data import json_dataset
  from pytorchvideo.data.clip_sampling import make_clip_sampler
  from pytorchvideo.data.labeled_video_dataset import LabeledVideoDataset
  from utils import temp_frame_video_dataset
label_desc: Use image node_id 3 for calling the TestJsonDatasets obj's underlying member method code with example usage: obj.test_recognition_uniform_clip_sampler() without return types