code: def test_underscoring():
      # Pairs taken from inflection tests
      # https://github.com/jpvanhal/inflection/blob/663982e/test_inflection.py#L113-L125
      pairs = (
          ("Product", "product"),
          ("SpecialGuest", "special_guest"),
          ("ApplicationController", "application_controller"),
          ("Area51Controller", "area51_controller"),
          ("HTMLTidy", "html_tidy"),
          ("HTMLTidyGenerator", "html_tidy_generator"),
          ("FreeBSD", "free_bsd"),
          ("HTML", "html"),
      )
  
      for camel, underscored in pairs:
          assert ci.cifti2._underscore(camel) == underscored
  
imports: import collections
  from xml.etree import ElementTree
  import numpy
  import pytest
  from nibabel import cifti2
  from nibabel.cifti2.cifti2 import Cifti2HeaderError, _float_01, _value_if_klass
  from nibabel.nifti2 import Nifti2Header
  from nibabel.tests.test_dataobj_images import TestDataobjAPI
  from nibabel.tests.test_image_api import DtypeOverrideMixin, SerializeMixin
label_desc: Use image node_id 16 for calling a global function with example usage: test_underscoring() without return types