// note that the returned time can be before t.createTime,
	// especially in cases when the nextBookmarkTime method
	// give us the zero value of type Time
	// so buckedID can hold a negative value
	nextTime, ok := w.nextBookmarkTime(t.clock.Now(), t.bookmarkFrequency)
	if !ok {
		return false
	}
	bucketID := int64(nextTime.Sub(t.createTime) / time.Second)