class_docstr: Tests member functions of ClassyVideoDataset.
class_docstr_tok: ["Tests","member","functions","of","ClassyVideoDataset","."]
code: def test_max_length_clip_sampler(self):
      clip_sampler = MockClipSampler(full_size=1000)
      clip_sampler = MaxLengthClipSampler(clip_sampler, num_samples=64)
      count = 0
      for _clip_index in iter(clip_sampler):
          count += 1
      self.assertEqual(count, 64)
      self.assertEqual(len(clip_sampler), 64)
  
imports: import unittest
  import torch
  from classy_vision.dataset import build_dataset, register_dataset
  from classy_vision.dataset.classy_video_dataset import ClassyVideoDataset, MaxLengthClipSampler
  from classy_vision.dataset.core import ListDataset
  from classy_vision.dataset.transforms.util_video import build_video_field_transform_default
  from torch.utils.data import Sampler
label_desc: Use image node_id 3 for calling the TestClassyVideoDataset obj's underlying member method code with example usage: obj.test_max_length_clip_sampler() without return types