code: def start(io_loop=None, check_time=2):
  
      
      io_loop = io_loop or asyncio.get_event_loop()
      if io_loop in _io_loops:
          return
      _io_loops[io_loop] = True
      if len(_io_loops) > 1:
          logger.warning("aiohttp_autoreload started more than once in the same process")
      # if _has_execv:
      #     add_reload_hook(functools.partial(io_loop.close, all_fds=True))
      modify_times = {}
      callback = functools.partial(_reload_on_update, modify_times)
      logger.debug("Starting periodic checks for code changes")
      call_periodic(check_time, callback, loop=io_loop)
docs: Begins watching source files for changes.
  
      .. versionchanged:: 4.1
         The ``io_loop`` argument is deprecated.