parameters: (self, devices, reason='unknown')
docstring: Adds devices to blacklist file.
  
      Args:
        devices: list of bad devices to be added to the blacklist file.
        reason: string specifying the reason for blacklist (eg: 'unauthorized')
docstring_summary: Adds devices to blacklist file.
docstring_tokens: Adds devices to blacklist file .
function: def Extend(self, devices, reason='unknown'):
      """Adds devices to blacklist file.
  
      Args:
        devices: list of bad devices to be added to the blacklist file.
        reason: string specifying the reason for blacklist (eg: 'unauthorized')
      """
      timestamp = time.time()
      event_info = {
          'timestamp': timestamp,
          'reason': reason,
      }
      device_dicts = {device: event_info for device in devices}
      logger.info('Adding %s to blacklist %s for reason: %s',
                   ','.join(devices), self._path, reason)
      with self._blacklist_lock:
        blacklist = self.Read()
        blacklist.update(device_dicts)
        self.Write(blacklist)
function_tokens: def Extend ( self , devices , reason = 'unknown' ) : timestamp = time . time ( ) event_info = { 'timestamp' : timestamp , 'reason' : reason , } device_dicts = { device : event_info for device in devices } logger . info ( 'Adding %s to blacklist %s for reason: %s' , ',' . join ( devices ) , self . _path , reason ) with self . _blacklist_lock : blacklist = self . Read ( ) blacklist . update ( device_dicts ) self . Write ( blacklist )