class_docstr: Stores data in temp buckets, restitute it shuffled.
code: def _iter_buckets(self):
      for bucket in self._buckets:
          bucket_data = sorted(bucket.read_values())
          bucket.del_file()
          for hkey, data in bucket_data:
              yield hkey, data
  
imports: import math
  import os
  import struct
  from typing import Iterator, List, Optional
  import uuid
  from absl import logging
  import six
  from tensorflow_datasets.core import hashing
  from tensorflow_datasets.core.utils import file_utils
  from tensorflow_datasets.core.utils import type_utils
  from tensorflow_datasets.core.utils.lazy_imports_utils import tensorflow
label_desc: Use image node_id 9 for calling the Shuffler obj's underlying member method code with example usage: obj._iter_buckets() without return types