code: def import_json():
    
  
    global _json_module
  
    if _json_module is not None:
      return _json_module
  
    else:
      try:
        module = __import__('json')
  
      # The 'json' module is available in Python > 2.6, and thus this exception
      # should not occur in all supported Python installations (> 2.6) of TUF.
      except ImportError: #pragma: no cover
        raise ImportError('Could not import the json module')
  
      else:
        _json_module = module
        return module
docs: <Purpose>
      Tries to import json module. We used to fall back to the simplejson module,
      but we have dropped support for that module. We are keeping this interface
      intact for backwards compatibility.
  
    <Arguments>
      None.
  
    <Exceptions>
      ImportError: on failure to import the json module.
  
    <Side Effects>
      None.
  
    <Return>
      json module