eventCount:         5,
			cacheCapacity:      5,
			lowerBoundCapacity: 5 / 2,
			upperBoundCapacity: 5 * 2,
			interval:           eventFreshDuration / 6,
			expectCapacity:     10,
			expectStartIndex:   0,
		},
		{
			name:               "[capacity not equals 4*n] events outside eventFreshDuration without change cache capacity",

// - decreases capacity by 2x when recent quarter of events occurred outside of eventFreshDuration(protect watchCache from flapping).
func (w *watchCache) resizeCacheLocked(eventTime time.Time) {
	if w.isCacheFullLocked() && eventTime.Sub(w.cache[w.startIndex%w.capacity].RecordTime) < eventFreshDuration {
		capacity := min(w.capacity*2, w.upperBoundCapacity)

	storageWatchListPageSize = int64(10000)
	// defaultBookmarkFrequency defines how frequently watch bookmarks should be send
	// in addition to sending a bookmark right before watch deadline.
	//
	// NOTE: Update `eventFreshDuration` when changing this value.
	defaultBookmarkFrequency = time.Minute
)

// Config contains the configuration for a given Cache.
type Config struct {
	// An underlying storage.Interface.
	Storage storage.Interface