presto-main/src/main/java/io/prestosql/sql/planner/Plan.java/Plan/Plan
class Plan:    public Plan(PlanNode root, TypeProvider types, StatsAndCosts statsAndCosts)
    {
        this.root = requireNonNull(root, "root is null");
        this.types = requireNonNull(types, "types is null");
        this.statsAndCosts = requireNonNull(statsAndCosts, "statsAndCosts is null");
    }