code: def generate_index_meta(self):
      meta = {}
      meta["node"] = {}
      meta["node"]["features"] = {}
      meta["node"]["features"][
          "graph_label"
      ] = "graph_label:string:uint64_t:hash_index"
      meta["edge"] = {}
      meta_json = json.dumps(meta)
      print(meta_json)
      with open(self.meta_file, "w") as out:
          out.write(meta_json)
  
file_path: euler/tf_euler/python/dataset/mutag.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import json
  import urllib
  import zipfile
  import tqdm
  from tf_euler.python.dataset.multigraph_util import *
  from tf_euler.python.dataset.base_dataset import DataSet
label_desc: Use image node_id 2 for calling the MUTAG obj's underlying member method code with example usage: obj.generate_index_meta() without return types