code: def _builder_configs():
      """Creates a list of default builder configs."""
      configs = []
      for combined_challenge, domain, dataset_size in SHARDS_MAPPING:
          task = DOMAIN_TO_TASK[domain]
          # pytype: disable=wrong-keyword-args
          configs.append(
              BuilderConfig(
                  name=(
                      f"{domain}_{task}_"
                      f"combined_challenge_{str(combined_challenge).lower()}_"
                      f"{dataset_size}"
                  ),
                  domain=domain,
                  task=task,
                  combined_challenge=combined_challenge,
                  dataset_size=dataset_size,
              )
          )
          # pytype: enable=wrong-keyword-args
      return configs
  
imports: from __future__ import annotations
  import collections
  import dataclasses
  import functools
  import os
  from typing import Any, Dict, Generator, Optional, Sequence, Text, Tuple, Union
  import numpy
  from tensorflow_datasets.core.utils.lazy_imports_utils import tensorflow
  import tensorflow_datasets.public_api
  from tensorflow_datasets.rl_unplugged import rlu_common
label_desc: Use image node_id 1 for calling a global function with example usage: _builder_configs() and returns: configs