presto-main/src/main/java/io/prestosql/sql/planner/plan/DistinctLimitNode.java/DistinctLimitNode/replaceChildren
class DistinctLimitNode:    @Override
    public PlanNode replaceChildren(List<PlanNode> newChildren)
    {
        return new DistinctLimitNode(getId(), Iterables.getOnlyElement(newChildren), limit, partial, distinctSymbols, hashSymbol);
    }