n := len(heap)
	if i >= n {
		badTimer()
	}
	if i*timerHeapN+1 >= n {
		return
	}
	tw := heap[i]
	when := tw.when
	if when <= 0 {
		badTimer()
	}
	for {
		leftChild := i*timerHeapN + 1
		if leftChild >= n {
			break
		}
		w := when
		c := -1
		for j, tw := range heap[leftChild:min(leftChild+timerHeapN, n)] {
			if tw.when < w {
				w = tw.when