deriver.go

	// derive runes
	var runes []*apb.MatchAggregateCollections_RuneSet
	for rs, rstats := range quot.Runes {
		if rstats.Plays < minPlayRate {
			continue
		}

		// rs is rune set string
		// rstats is rune set subscalars
		runeSet, err := deserializeBonusSet(rs)
		if err != nil {
			return nil, fmt.Errorf("could not deserialize rune set: %v", err)
		}
		runes = append(runes, &apb.MatchAggregateCollections_RuneSet{
			Runes:      runeSet,
			PickRate:   rstats.Plays,
			WinRate:    rstats.Wins,
			NumMatches: uint32(rstats.PlayCount),
		})
	}

MatchAggregator.scala

    MatchAggregate.Collections(
      runes = quot.runes
        .filter(_._2.plays >= minPlayRate)  // Ensure minimum play rate is met
        .map { case (runeSet, subscalars) =>
          MatchAggregate.Collections.RuneSet(
            runes = deserializeBonusSet(runeSet),
            pickRate = subscalars.plays,
            winRate = subscalars.wins,
            numMatches = subscalars.playCount.toInt
          )
        }.toSeq