presto-main/src/main/java/io/prestosql/sql/planner/optimizations/AddLocalExchanges.java/AddLocalExchanges/visitTableFinish
class AddLocalExchanges:        @Override
        public PlanWithProperties visitTableFinish(TableFinishNode node, StreamPreferredProperties parentPreferences)
        {
            // table commit requires that all data be in one stream
            // this node changes the input organization completely, so we do not pass through parent preferences
            return planAndEnforceChildren(node, singleStream(), defaultParallelism(session));
        }