new_contents: #!/usr/bin/env python
  # coding=utf-8
  import json_config
  import os
  
  config = json_config.connect('categories.json')
  
  config['comics']['dc']['batman']['antagonists'] = ['Scarecrow', 'The Joker', 'Bane']
  config['comics']['marvel']['ironman']['antagonists'] = 'Ultron'
  
  print(config.serialize())
  
  os.remove('categories.json')
  
subject: add example