code: def test_callback():
      for device in ["cpu", "gpu"]:
          for as_tensors in [False, True]:
              for change_layout in [None, "AB"]:
                  yield _test_callback, device, as_tensors, change_layout
  
imports: import random
  import nvidia.dali.fn
  import nvidia.dali.ops
  import nvidia.dali.types
  import numpy
  from nvidia.dali import Pipeline, pipeline_def
  from test_utils import check_batch
  from nose_utils import raises, assert_warns, assert_raises
  from nvidia.dali.types import DALIDataType
  from numpy.random import default_rng
label_desc: Use image node_id 5 for calling a global function with example usage: test_callback() without return types