code: def testMaterializeFeaturesFromTfExample(self):
      example1 = self._makeExample(
          age=3.0, language="english", label=1.0
      )
  
      extracts = {constants.INPUT_KEY: example1.SerializeToString()}
      input_example = extracts[constants.INPUT_KEY]
      result = feature_extractor._MaterializeFeatures(
          extracts, source=constants.INPUT_KEY
      )
      self.assertIsInstance(result, dict)
      self.assertEqual(
          result[constants.INPUT_KEY], input_example
      )  # should still be there.
      self.assertEqual(
          result["features__age"],
          types.MaterializedColumn(name="features__age", value=[3.0]),
      )
      self.assertEqual(
          result["features__language"],
          types.MaterializedColumn(
              name="features__language", value=[b"english"]
          ),
      )
      self.assertEqual(
          result["features__label"],
          types.MaterializedColumn(name="features__label", value=[1.0]),
      )
  
file_path: model-analysis/tensorflow_model_analysis/extractors/legacy_feature_extractor_test.py
imports: import os
  import tempfile
  import numpy
  import tensorflow
  from tensorflow_model_analysis import constants
  from tensorflow_model_analysis.api import types
  from tensorflow_model_analysis.eval_saved_model import encoding
  from tensorflow_model_analysis.eval_saved_model import testutil
  from tensorflow_model_analysis.extractors import legacy_feature_extractor
label_desc: Use image node_id 7 for calling the BuildDiagnosticsTableTest obj's underlying member method code with example usage: obj.testMaterializeFeaturesFromTfExample() without return types