presto-main/src/main/java/io/prestosql/cost/PlanNodeStatsEstimateMath.java/PlanNodeStatsEstimateMath/createZeroStats
class PlanNodeStatsEstimateMath:    private static PlanNodeStatsEstimate createZeroStats(PlanNodeStatsEstimate stats)
    {
        PlanNodeStatsEstimate.Builder result = PlanNodeStatsEstimate.builder();
        result.setOutputRowCount(0);
        stats.getSymbolsWithKnownStatistics().forEach(symbol -> result.addSymbolStatistics(symbol, SymbolStatsEstimate.zero()));
        return result.build();
    }