func (e *lockedLastMinuteLatency) addSize(value time.Duration, sz int64) {
	// alloc on every call, so we have a clean entry to swap in.
	t := time.Now().Unix()
	e.init.Do(func() {
		e.cached.Store(&AccElem{})
		atomic.StoreInt64(&e.cachedSec, t)
	})
	acc := e.cached.Load()
	if lastT := atomic.LoadInt64(&e.cachedSec); lastT != t {
		// Check if lastT was changed by someone else.
		if atomic.CompareAndSwapInt64(&e.cachedSec, lastT, t) {