presto-main/src/main/java/io/prestosql/sql/planner/plan/UnnestNode.java/UnnestNode/getOutputSymbols
class UnnestNode:    @Override
    public List<Symbol> getOutputSymbols()
    {
        ImmutableList.Builder<Symbol> outputSymbolsBuilder = ImmutableList.<Symbol>builder()
                .addAll(replicateSymbols)
                .addAll(Iterables.concat(unnestSymbols.values()));
        ordinalitySymbol.ifPresent(outputSymbolsBuilder::add);
        return outputSymbolsBuilder.build();
    }