code: def convert2json(self, convert_dir, out_dir):
      prefix = os.path.join(self.data_dir, "MUTAG_")
      adj_list = read_adj(prefix + "A.txt")
      graph_indicator = read_graph_indicator(
          prefix + "graph_indicator.txt"
      )
      graph_label = read_graph_label(prefix + "graph_labels.txt")
      node_label = read_node_label(prefix + "node_labels.txt")
      self.generate_index_meta()
      with open(out_dir, "w") as out:
          out.write(
              gen_graph_json(
                  adj_list, graph_indicator, graph_label, node_label
              )
          )
      with open(self.id_file, "w") as id_out:
          start_idx = int(self.total_size * self.train_rate)
          for i in range(start_idx, self.total_size):
              id_out.write(str(i) + "\n")
  
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 4 for calling the MUTAG obj's underlying member method code with example usage: obj.convert2json(convert_dir, out_dir) without return types