presto-main/src/main/java/io/prestosql/operator/exchange/LocalExchange.java/LocalExchange/newSinkFactoryId
class LocalExchange:        public synchronized LocalExchangeSinkFactoryId newSinkFactoryId()
        {
            checkState(!noMoreSinkFactories);
            LocalExchangeSinkFactoryId result = new LocalExchangeSinkFactoryId(numSinkFactories);
            numSinkFactories++;
            return result;
        }