presto-main/src/main/java/io/prestosql/sql/planner/optimizations/QueryCardinalityUtil.java/CardinalityExtractorPlanVisitor/visitPlan
class CardinalityExtractorPlanVisitor:        @Override
        protected Range<Long> visitPlan(PlanNode node, Void context)
        {
            return Range.atLeast(0L);
        }