docs: def config_absent(name):
      '''
      Ensure configuration property is absent in /usbkey/config
  
      name : string
          name of property
  
      '''
      name = name.lower()
      ret = {'name': name,
             'changes': {},
             'result': None,
             'comment': ''}
  
      # load configuration
      config = _load_config()
  
      if name in config:
          # delete property
          ret['result'] = True
          ret['comment'] = 'property {0} deleted'.format(name)
          ret['changes'][name] = None
          del config[name]
      else:
          # we're good
          ret['result'] = True
          ret['comment'] = 'property {0} is absent'.format(name)
  
      # apply change if needed
      if not __opts__['test'] and ret['changes']:
          ret['result'] = _write_config(config)
  
      return ret