code: def service_timeouts(cls):
          
          timer_manager = cls._timers
          while True:
              next_end = timer_manager.service_timeouts()
              sleep_time = max(next_end - time.time(), 0) if next_end else 10000
              cls._new_timer.wait(sleep_time)
              cls._new_timer.clear()
docs: cls._timeout_watcher runs in this loop forever.
          It is usually waiting for the next timeout on the cls._new_timer Event.
          When new timers are added, that event is set so that the watcher can
          wake up and possibly set an earlier timeout.