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