code: def test_lowercase_text(self):
      txt = [
          "Punctuation and digits: -*/+$#%@%$123456789#^$*%&",
          "Non-latin UTF8 chars: ΘͽʦȺЩ",
          "Accented chars: ĎÔPQRŔSŠoóôpqrŕsštťuúvwxyý",
          "Non-UTF8-letters: e.g. ◆, ♥, and the emoji symbol ( ͡° ͜ʖ ͡°)",
          "Folded: ßς",
          "",
      ]
      expected = [
          _Utf8("punctuation and digits: -*/+$#%@%$123456789#^$*%&"),
          _Utf8("non-latin utf8 chars: θͽʦⱥщ"),
          _Utf8("accented chars: ďôpqrŕsšoóôpqrŕsštťuúvwxyý"),
          _Utf8(
              "non-utf8-letters: e.g. ◆, ♥, and the emoji symbol ( ͡° ͜ʖ ͡°)"
          ),
          _Utf8("folded: ssσ"),
          b"",
      ]
      self.assertAllEqual(expected, normalize_ops.case_fold_utf8(txt))
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops.ragged import ragged_factory_ops
  from tensorflow.python.platform import test
  from tensorflow_text.python.ops import normalize_ops
label_desc: Use image node_id 2 for calling the NormalizeOpsTest obj's underlying member method code with example usage: obj.test_lowercase_text() without return types