uber-go 中的 ratelimit 包, 为何 sleepFor 不能小于 maxSlack 呢?

Take方法见: https://github.com/uber-go/ratelimit/blob/master/limiter_atomic.go

其中有一段代码:

...
		if newState.sleepFor < t.maxSlack {
			newState.sleepFor = t.maxSlack
		}
...

sleepFor是“间隔时间-上次执行时间至当前时间”, 例如间隔时间为 1 秒, 上次执行时间为 5 秒前, sleepFor 就是-4

sleepFor在末尾用于t.clock.Sleep(newState.sleepFor)，貌似没有别的用途，那为什么需要让它不能小于t.maxSlack？

或者如果有 dalao 明白这段注释的意思也可以解释一下:

...
		// We shouldn't allow sleepFor to get too negative, since it would mean that
		// a service that slowed down a lot for a short period of time would get
		// a much higher RPS following that.
...

萌新提问, 感谢~