code: def testStringifySliceKey(self):
      test_cases = [
          ("overall", (), "Overall"),
          ("one bytes feature", (("age_str", "5"),), "age_str:5"),
          ("one int64 feature", (("age", 1),), "age:1"),
          (
              "mixed",
              (("age", 1), ("gender", "f")),
              "age_X_gender:1_X_f",
          ),
          (
              "more",
              (("age", 1), ("gender", "f"), ("interest", "cars")),
              "age_X_gender_X_interest:1_X_f_X_cars",
          ),
          (
              "unicode",
              (("text", b"\xe4\xb8\xad\xe6\x96\x87"),),
              "text:\u4e2d\u6587",
          ),
      ]  # pyformat: disable
      for name, slice_key, stringified_key in test_cases:
          self.assertEqual(
              stringified_key,
              slicer.stringify_slice_key(slice_key),
              msg=name,
          )
  
imports: from absl.testing import parameterized
  import apache_beam
  from apache_beam.testing import util
  import numpy
  import six
  import tensorflow
  from tensorflow_model_analysis import constants
  from tensorflow_model_analysis.api import types
  from tensorflow_model_analysis.eval_saved_model import testutil
  from tensorflow_model_analysis.extractors import slice_key_extractor
  from tensorflow_model_analysis.post_export_metrics import metric_keys
  from tensorflow_model_analysis.proto import config_pb2
  from tensorflow_model_analysis.proto import metrics_for_slice_pb2
  from tensorflow_model_analysis.slicer import slicer_lib
  from google.protobuf import text_format
label_desc: Use image node_id 12 for calling the SlicerTest obj's underlying member method code with example usage: obj.testStringifySliceKey() without return types