code: def __len__(self) -> int:
      return len(self.images)
  
file_path: vision/torchvision/datasets/voc.py
imports: import collections
  import os
  from xml.etree.ElementTree import Element
  from .vision import VisionDataset
  from typing import Any, Callable, Dict, List, Optional, Tuple
  from PIL import Image
  from .utils import download_and_extract_archive, verify_str_arg
label_desc: Use image node_id 2 for calling the _VOCBase obj's underlying member method code with example usage: obj.__len__() and returns: len