presto-main/src/main/java/io/prestosql/sql/planner/plan/TopNRowNumberNode.java/TopNRowNumberNode/getOutputSymbols
class TopNRowNumberNode:    @Override
    public List<Symbol> getOutputSymbols()
    {
        if (!partial) {
            return ImmutableList.copyOf(concat(source.getOutputSymbols(), ImmutableList.of(rowNumberSymbol)));
        }
        return ImmutableList.copyOf(source.getOutputSymbols());
    }