code: def send_notification(self, code, subcode):
          
          notification = BGPNotification(code, subcode)
          reason = notification.reason
          self._send_with_lock(notification)
          self._signal_bus.bgp_error(self._peer, code, subcode, reason)
          if len(self._localname):
              LOG.error('Sent notification to %r >> %s', self._localname,
                        notification)
          self._socket.close()
docs: Utility to send notification message.
  
          Closes the socket after sending the message.
          :Parameters:
              - `socket`: (socket) - socket over which to send notification
               message.
              - `code`: (int) - BGP Notification code
              - `subcode`: (int) - BGP Notification sub-code
  
          RFC ref: http://tools.ietf.org/html/rfc4486
          http://www.iana.org/assignments/bgp-parameters/bgp-parameters.xhtml