code: func NewRankCache(maxEntries uint32) *rankCache {
  	return &rankCache{
  		maxEntries:      maxEntries,
  		thresholdBuffer: int(thresholdFactor * float64(maxEntries)),
  		entries:         make(map[uint64]uint64),
  		stats:           stats.NopStatsClient,
  	}
  }
docs: // NewRankCache returns a new instance of RankCache.