code: def infuse_metadata(graph_def, info):
    
    temp_graph = tf.Graph()
    with temp_graph.as_default():
      tf.constant(json.dumps(info, cls=NumpyJSONEncoder), name=metadata_node_name)
    meta_node = temp_graph.as_graph_def().node[0]
    graph_def.node.extend([meta_node])
docs: Embed meta data as a string constant in a TF graph.
  
    This function takes info, converts it into json, and embeds
    it in graph_def as a constant op called `__lucid_metadata_json`.