code: def __len__(self):
      return len(self.batches)
  
imports: import io
  import json
  import logging
  import pickle
  from collections import OrderedDict
  from typing import Any
  import braceexpand
  import numpy
  import webdataset
  from torch.utils.data import IterableDataset
  from nemo.collections.nlp.data.data_utils.data_preprocessing import dataset_to_ids
  from nemo.core import Dataset
label_desc: Use image node_id 2 for calling the SentenceDataset obj's underlying member method code with example usage: obj.__len__() and returns: len