class_docstr: COCO Custom Dataset compatible with torch.utils.data.DataLoader.
class_docstr_tok: ["COCO","Custom","Dataset","compatible","with","torch.utils.data.DataLoader","."]
code: def __len__(self):
      return len(self.ids)
  
file_path: pytorch-tutorial/tutorials/03-advanced/image_captioning/data_loader.py
imports: import torch
  import torchvision.transforms
  import torch.utils.data
  import os
  import pickle
  import numpy
  import nltk
  from PIL import Image
  from build_vocab import Vocabulary
  from pycocotools.coco import COCO
label_desc: Use image node_id 3 for calling the CocoDataset obj's underlying member method code with example usage: obj.__len__() and returns: len