code: async def restart(request: web.Request) -> web.Response:
      
      session = session_from_request(request)
      if session and session.stage != Stages.READY_FOR_RESTART:
          return web.json_response(
              data={'error': 'not-ready',
                    'message': 'System is not ready to restart '
                    f'(currently {session.stage.value.short})'},
              status=409)
  
      asyncio.get_event_loop().call_later(1, dbus_actions.restart)
      return web.json_response({'message': 'Restarting in 1s'},
                               status=200)
docs: Serves /update/server/restart