class_docstr: Stores data in temp buckets, restitute it shuffled.
code: def _add_to_bucket(self, hkey, data):
      bucket_number = get_bucket_number(
          hkey=hkey, num_buckets=BUCKETS_NUMBER
      )
      self._buckets[bucket_number].add(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 4 for calling the Shuffler obj's underlying member method code with example usage: obj._add_to_bucket(hkey, data) without return types