code: def test_add_feature_input_output(self):
      writer = metadata_writer.MetadataWriter.create(
          self.image_classifier_model_buffer
      )
      writer.add_general_info(
          model_name="my_model", model_description="my_description"
      )
      writer.add_feature_input(
          name="input_tesnor", description="a feature input tensor"
      )
      writer.add_feature_output(
          name="output_tesnor", description="a feature output tensor"
      )
  
      _, metadata_json = writer.populate()
      self.assertJsonEqual(
          metadata_json,
          """{
            "name": "my_model",
            "description": "my_description",
            "subgraph_metadata": [
              {
                "input_tensor_metadata": [
                  {
                    "name": "input_tesnor",
                    "description": "a feature input tensor",
                    "content": {
                      "content_properties_type": "FeatureProperties",
                      "content_properties": {
                      }
                    },
                    "stats": {
                    }
                  }
                ],
                "output_tensor_metadata": [
                  {
                    "name": "output_tesnor",
                    "description": "a feature output tensor",
                    "content": {
                      "content_properties_type": "FeatureProperties",
                      "content_properties": {
                      }
                    },
                    "stats": {
                    }
                  }
                ]
              }
            ],
            "min_parser_version": "1.0.0"
          }
          """,
      )
  
imports: import os
  import tempfile
  from absl.testing import absltest
  from mediapipe.tasks.metadata import metadata_schema_py_generated
  from mediapipe.tasks.python.metadata.metadata_writers import metadata_info
  from mediapipe.tasks.python.metadata.metadata_writers import metadata_writer
  from mediapipe.tasks.python.test import test_utils
label_desc: Use image node_id 3 for calling the MetadataWriterForTaskTest obj's underlying member method code with example usage: obj.test_add_feature_input_output() without return types