presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/PruneLimitColumns.java/PruneLimitColumns/pushDownProjectOff
class PruneLimitColumns:    @Override
    protected Optional<PlanNode> pushDownProjectOff(PlanNodeIdAllocator idAllocator, LimitNode limitNode, Set<Symbol> referencedOutputs)
    {
        Set<Symbol> prunedLimitInputs = ImmutableSet.<Symbol>builder()
                .addAll(referencedOutputs)
                .addAll(limitNode.getTiesResolvingScheme()
                        .map(OrderingScheme::getOrderBy)
                        .orElse(ImmutableList.of()))
                .build();

        return restrictChildOutputs(idAllocator, limitNode, prunedLimitInputs);
    }