code: func (t *Timer) Stop() {
  	if atomic.LoadInt32(&t.closed) > 0 {
  		return
  	}
  
  	// guarantee that logic is not blocked
  	if len(Manager.ChClosingTimer) < timerBacklog {
  		Manager.ChClosingTimer <- t.ID
  		atomic.StoreInt32(&t.closed, 1)
  	} else {
  		t.counter = 0 // automatically closed in next Cron
  	}
  }
docs: // Stop turns off a timer. After Stop, fn will not be called forever