<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def infuse_metadata(graph_def, info):
 """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`. """

  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])