code: def set_epoch(self, epoch: int):
      # set by trainer when train on new epoch or restore from a checkpoint
      logging.info(f"set epoch to {epoch} in airstore dataset")
      self.epoch = epoch
  
file_path: vissl/vissl/data/airstore_dataset.py
imports: import io
  import logging
  from typing import Any, Iterable, Tuple
  import torch
  from classy_vision.generic.distributed_util import get_rank, get_world_size
  from iopath.common.file_io import PathManager
  from PIL import Image, ImageFile
  from vissl.config import AttrDict
  from vissl.data.data_helper import get_mean_image, QueueDataset
label_desc: Use image node_id 2 for calling the AirstoreDataset obj's underlying member method code with example usage: obj.set_epoch(epoch) without return types