code: def test_preemphasis_operator():
      for device in ["cpu", "gpu"]:
          for batch_size in [1, 3, 128]:
              for border in ["zero", "clamp", "reflect"]:
                  for coef, per_sample_coeff in [
                      (0.97, False),
                      (0.0, False),
                      (None, True),
                  ]:
                      yield (
                          check_preemphasis_operator,
                          device,
                          batch_size,
                          border,
                          coef,
                          per_sample_coeff,
                      )
  
file_path: DALI/dali/test/python/operator_2/test_preemph.py
imports: from nvidia.dali.pipeline import Pipeline
  import nvidia.dali.ops
  import nvidia.dali.fn
  import numpy
  from functools import partial
  from test_utils import compare_pipelines
  from test_utils import RandomlyShapedDataIterator
label_desc: Use image node_id 3 for calling a global function with example usage: test_preemphasis_operator() without return types