code: def test_get_feature_value_slicer_non_utf8_slice_key(self):
      features = {"a": None}
      input_record_batch = pa.RecordBatch.from_arrays(
          [
              pa.array([[b"\xF0"], ["cat"]]),
          ],
          ["a"],
      )
      with self.assertRaisesRegex(ValueError, "must be valid UTF-8"):
          _ = list(
              slicing_util.get_feature_value_slicer(features)(
                  input_record_batch
              )
          )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import sys
  import unittest
  from absl.testing import absltest
  import apache_beam
  from apache_beam.testing import util
  import pyarrow
  from tensorflow_data_validation import constants
  from tensorflow_data_validation.utils import slicing_util
  from tfx_bsl.public.proto import slicing_spec_pb2
  from google.protobuf import text_format
label_desc: Use image node_id 9 for calling the SlicingUtilTest obj's underlying member method code with example usage: obj.test_get_feature_value_slicer_non_utf8_slice_key() without return types