code: def reset(self):
          
          if self.state is not TimerState.stopped:
              if self.on_reset and self.state is TimerState.overflow:
                  if callable(self.on_reset):
                      self.on_reset()
                  else:
                      execute(self.on_reset)
              self.state = TimerState.stopped
docs: Stop timer and execute ``on_reset`` if overflow occured.