presto-main/src/main/java/io/prestosql/cost/CostCalculatorUsingExchanges.java/CostCalculatorUsingExchanges/calculateCost
class CostCalculatorUsingExchanges:    @Override
    public PlanCostEstimate calculateCost(PlanNode node, StatsProvider stats, CostProvider sourcesCosts, Session session, TypeProvider types)
    {
        CostEstimator costEstimator = new CostEstimator(stats, sourcesCosts, types, taskCountEstimator);
        return node.accept(costEstimator, null);
    }