code: def set(self, time_sec, callback_fn, *args, **kwdargs):
          
          timer = self.timer()
          timer.set_callback('expired', callback_fn, *args, **kwdargs)
          timer.set(time_sec)
          return timer
docs: Convenience function to create and set a timer.
  
          Equivalent to:
              timer = timer_factory.timer()
              timer.set_callback('expired', callback_fn, *args, **kwdargs)
              timer.set(time_sec)