presto-main/src/main/java/io/prestosql/cost/CostCalculatorWithEstimatedExchanges.java/ExchangeCostEstimator/visitJoin
class ExchangeCostEstimator:        @Override
        public LocalCostEstimate visitJoin(JoinNode node, Void context)
        {
            return calculateJoinExchangeCost(
                    node.getLeft(),
                    node.getRight(),
                    stats,
                    types,
                    Objects.equals(node.getDistributionType(), Optional.of(JoinNode.DistributionType.REPLICATED)),
                    taskCountEstimator.estimateSourceDistributedTaskCount());
        }