code: def _closing_iter(self, dataloader):
      yield from dataloader
      dataloader.__exit__(None, None, None)
  
imports: import logging
  from typing import Dict, List, Optional
  import pytorch_lightning
  import torch
  from petastorm import make_batch_reader
  from petastorm.pytorch import DataLoader, decimal_friendly_collate
  from reagent.core.oss_tensorboard_logger import OssTensorboardLogger
  from reagent.data.spark_utils import get_spark_session
  from reagent.preprocessing.batch_preprocessor import BatchPreprocessor
  from reagent.training import StoppingEpochCallback
  from reagent.training.reagent_lightning_module import has_test_step_override
  from .types import Dataset, ReaderOptions, ResourceOptions
label_desc: Use image node_id 2 for calling the PetastormLightningDataModule obj's underlying member method code with example usage: obj._closing_iter(dataloader) without return types