code: def testDocumentSuccess(self):
      documented_test_key = tfx_doc_controls.documented(
          "test key", "test value"
      )
      self.assertEqual(1, len(tfx_doc_controls.EXTRA_DOCS))
      self.assertEqual(
          "test value",
          tfx_doc_controls.EXTRA_DOCS.get(id(documented_test_key)),
      )
  
imports: import tensorflow
  from tfx.utils import doc_controls
  from tensorflow.tools.docs import doc_controls
label_desc: Use image node_id 2 for calling the DocControlsTest obj's underlying member method code with example usage: obj.testDocumentSuccess() without return types