presto-main/src/main/java/io/prestosql/cost/SemiJoinStatsCalculator.java/SemiJoinStatsCalculator/computeSemiJoin
class SemiJoinStatsCalculator:    public static PlanNodeStatsEstimate computeSemiJoin(PlanNodeStatsEstimate sourceStats, PlanNodeStatsEstimate filteringSourceStats, Symbol sourceJoinSymbol, Symbol filteringSourceJoinSymbol)
    {
        return compute(sourceStats, filteringSourceStats, sourceJoinSymbol, filteringSourceJoinSymbol,
                (sourceJoinSymbolStats, filteringSourceJoinSymbolStats) ->
                        min(filteringSourceJoinSymbolStats.getDistinctValuesCount(), sourceJoinSymbolStats.getDistinctValuesCount()));
    }