presto-main/src/main/java/io/prestosql/operator/exchange/LocalExchangeSinkOperator.java/LocalExchangeSinkOperator/noMoreOperators
class LocalExchangeSinkOperator:        @Override
        public void noMoreOperators()
        {
            if (!closed) {
                closed = true;
                localExchangeFactory.closeSinks(sinkFactoryId);
            }
        }