code: def serialize_feature_metadata(output_dict: Dict[str, Any]) -> bytes:
      """Returns a blob of serialized feature metadata.
  
      Args:
        output_dict: Output dictionary in the format returned by _observe_dnn_model.
  
      Returns:
        Blob of serialized feature metdata.
      """
      dump_dict = {}
      if "dnn_model" in output_dict:
          dump_dict[
              "dnn_model"
          ] = _serialize_feature_metadata_for_model(
              output_dict["dnn_model_cols_to_output_tensors"],
              output_dict["dnn_model_features"],
          )
  
      return pickle.dumps(dump_dict)
  
imports: import contextlib
  import inspect
  import os
  import pickle
  from typing import Any, Callable, Dict, Optional
  import six
  import tensorflow
  from tensorflow import estimator
  import tensorflow_model_analysis
  from tensorflow_model_analysis.api import types
  from tensorflow_model_analysis.utils import util
  from tensorflow.python.feature_column import feature_column_v2
  from tensorflow_estimator.python.estimator.canned import dnn
label_desc: Use image node_id 8 for calling a global function with example usage: serialize_feature_metadata(output_dict) and returns: pickle