code: def __len__(self):
      return len(self._dataset)
  
imports: from __future__ import annotations
  import collections.abc
  import contextlib
  from collections import defaultdict
  from copy import copy
  import torch
  from torchvision import datasets, tv_tensors
  from torchvision.transforms.v2 import functional
label_desc: Use image node_id 4 for calling the VisionDatasetTVTensorWrapper obj's underlying member method code with example usage: obj.__len__() and returns: len