code: def test_count_missing_generator_key(self):
      path = types.FeaturePath(["feature"])
      generator = count_missing_generator.CountMissingGenerator(path)
      expected_key = ("CountMissingGenerator", path)
      # use assertDictEqual to make failures readable while checking hash value.
      self.assertDictEqual(
          {expected_key: None}, {generator.get_key(): None}
      )
      self.assertDictEqual(
          {expected_key: None},
          {
              count_missing_generator.CountMissingGenerator.key(
                  path
              ): None
          },
      )
  
file_path: data-validation/tensorflow_data_validation/statistics/generators/constituents/count_missing_generator_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import absltest
  import pyarrow
  from tensorflow_data_validation import types
  from tensorflow_data_validation.statistics.generators import input_batch
  from tensorflow_data_validation.statistics.generators.constituents import count_missing_generator
label_desc: Use image node_id 1 for calling the CountMissingGeneratorTest obj's underlying member method code with example usage: obj.test_count_missing_generator_key() without return types