class SchedulingOrderVisitor {

    public static List<PlanNodeId> scheduleOrder(PlanNode root)
    {
        ImmutableList.Builder<PlanNodeId> schedulingOrder = ImmutableList.builder();
        root.accept(new Visitor(schedulingOrder::add), null);
        return schedulingOrder.build();
    }

    private  SchedulingOrderVisitor();

}