class_docstr: A common dataset object shared by most of NeMo multimodal models.
code: def __iter__(self):
      ds_iter = self._dataset.__iter__()
      while self.skip_ahead > 0 and not self.infinite_sampler:
          try:
              _ = next(ds_iter)
              self.skip_ahead -= (
                  self.data_parallel_size * self.num_workers
              )
          except StopIteration:
              self.skip_ahead = 0
      return ds_iter
  
imports: import io
  import itertools
  import json
  import os
  import pickle
  import random
  import re
  from typing import Callable, List, Union
  import boto3
  import torch.distributed
  from botocore.config import Config
  from PIL import Image
  from nemo.collections.multimodal.data.common.data_samplers import SharedEpoch, WDSUrlsRandomSampler
  from nemo.collections.multimodal.data.common.webdataset_s3 import WebDataset
  from nemo.collections.nlp.modules.common.megatron.utils import ApexGuardDefaults
  from nemo.core.classes import IterableDataset
  from nemo.utils import logging
label_desc: Use image node_id 3 for calling the WebDatasetCommon obj's underlying member method code with example usage: obj.__iter__() and returns: ds_iter