code: def unfold_batches(batches, num_expand):
      return [unfold_batch(batch, num_expand) for batch in batches]
  
imports: import os
  import random
  import numpy
  from typing import List, Union, Callable, Optional
  from dataclasses import dataclass, field
  from nvidia.dali import pipeline_def
  import nvidia.dali.fn
  from nvidia.dali import types
  import nvidia.dali.tensors
  from test_utils import get_dali_extra_path, check_batch
label_desc: Use image node_id 5 for calling a global function with example usage: unfold_batches(batches, num_expand) and returns: unknown