code: def test_kernels():
      for device in ["cpu", "gpu"]:
          for num_dims in [1, 2, 3]:
              for normalize in [True, False]:
                  for smoothing in [True, False]:
                      yield _test_kernels, device, num_dims, smoothing, normalize
  
imports: from nvidia.dali.pipeline import pipeline_def
  import nvidia.dali.types
  import nvidia.dali.fn
  import numpy
  import cv2
  from scipy.ndimage import convolve1d, filters
  import os
  from nose_utils import assert_raises
  from nose.plugins.attrib import attr
  from sequences_test_utils import video_suite_helper, ArgCb
  from test_utils import get_dali_extra_path, check_batch, RandomlyShapedDataIterator
label_desc: Use image node_id 3 for calling a global function with example usage: test_kernels() without return types