presto-main/src/main/java/io/prestosql/operator/JoinStatisticsCounter.java/JoinStatisticsCounter/updateLookupSourcePositions
class JoinStatisticsCounter:    public void updateLookupSourcePositions(long lookupSourcePositionsDelta)
    {
        this.lookupSourcePositions = Optional.of(this.lookupSourcePositions.orElse(0L) + lookupSourcePositionsDelta);
    }