presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/PlanNodeWithCost.java/PlanNodeWithCost/PlanNodeWithCost
class PlanNodeWithCost:    public PlanNodeWithCost(PlanCostEstimate cost, PlanNode planNode)
    {
        this.cost = requireNonNull(cost, "cost is null");
        this.planNode = requireNonNull(planNode, "planNode is null");
    }