code: def save_checkpoint(self):
      for bucket in self.buckets:
          bucket.fh.flush()
  
      bucket_offsets = [bucket.fh.tell() for bucket in self.buckets]
      pickle.dump(bucket_offsets, open(self.checkpoint_file, "wb"))
  
imports: import argparse
  import json
  import pickle
  import os
  import sys
  from pathlib import Path
  import glob
  import signal
  from signal import SIGINT
  from tqdm import tqdm
  from lm_eval.decontamination.janitor import Janitor, word_ngrams
  from lm_eval.decontamination.archiver import TextArchive, Reader
  import logging
  from tqdm_multiprocess.logger import setup_logger_tqdm
label_desc: Use image node_id 3 for calling the Buckets obj's underlying member method code with example usage: obj.save_checkpoint() without return types