code: def test_to_snake_case_impl():
      fn_name_tests = [
          ("Test", "test"),
          ("OneTwo", "one_two"),
          ("TestXYZ", "test_xyz"),
          ("testX", "test_x"),
          ("TestXx", "test_xx"),
          ("testXX", "test_xx"),
          ("OneXYZTwo", "one_xyz_two"),
          ("MFCC", "mfcc"),
          ("RandomBBoxCrop", "random_bbox_crop"),
          ("STFT_CPU", "stft_cpu"),
          ("DOUBLE__UNDERSCORE", "double__underscore"),
          ("double__underscore", "double__underscore"),
          ("XYZ1ABC", "xyz1abc"),
          ("XYZ1abc", "xyz1abc"),
          ("trailing__", "trailing__"),
          ("TRAILING__", "trailing__"),
          ("Caffe2Reader", "caffe2_reader"),
          ("COCOReader", "coco_reader"),
          ("DLTensorPythonFunction", "dl_tensor_python_function"),
          ("TFRecordReader", "tfrecord_reader"),
          ("_Leading", "_leading"),
          ("_LEADing", "_lea_ding"),
          ("_LeAdIng", "_le_ad_ing"),
          ("_L_Eading", "_l_eading"),
      ]
  
      for inp, out in fn_name_tests:
          assert (
              fn._to_snake_case(inp) == out
          ), f"{fn._to_snake_case(inp)} != {out}"
  
imports: import nvidia.dali.fn
  import nvidia.dali.ops
  from nvidia.dali.pipeline import Pipeline
  import nvidia.dali.types
  import numpy
  from nose_utils import assert_raises
  import sys
  import inspect
  from nose.plugins.attrib import attr
  import nose
label_desc: Use image node_id 9 for calling a global function with example usage: test_to_snake_case_impl() without return types