presto-main/src/main/java/io/prestosql/sql/planner/optimizations/AddLocalExchanges.java/Rewriter/visitTopNRowNumber
class Rewriter:        @Override
        public PlanWithProperties visitTopNRowNumber(TopNRowNumberNode node, StreamPreferredProperties parentPreferences)
        {
            StreamPreferredProperties requiredProperties = parentPreferences.withDefaultParallelism(session);

            // final topN row number requires that all data be partitioned
            if (!node.isPartial()) {
                requiredProperties = requiredProperties.withPartitioning(node.getPartitionBy());
            }

            return planAndEnforceChildren(node, requiredProperties, requiredProperties);
        }