presto-main/src/main/java/io/prestosql/cost/SimpleStatsRule.java/SimpleStatsRule/calculate
class SimpleStatsRule:    @Override
    public final Optional<PlanNodeStatsEstimate> calculate(T node, StatsProvider sourceStats, Lookup lookup, Session session, TypeProvider types)
    {
        return doCalculate(node, sourceStats, lookup, session, types)
                .map(estimate -> normalizer.normalize(estimate, node.getOutputSymbols(), types));
    }