presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/ReorderJoins.java/JoinEnumerationResult/createJoinEnumerationResult
class JoinEnumerationResult:        static JoinEnumerationResult createJoinEnumerationResult(Optional<PlanNode> planNode, PlanCostEstimate cost)
        {
            if (cost.hasUnknownComponents()) {
                return UNKNOWN_COST_RESULT;
            }
            if (cost.equals(PlanCostEstimate.infinite())) {
                return INFINITE_COST_RESULT;
            }
            return new JoinEnumerationResult(planNode, cost);
        }