presto-main/src/main/java/io/prestosql/operator/exchange/LocalExchangeSink.java/LocalExchangeSink/LocalExchangeSink
class LocalExchangeSink:    public LocalExchangeSink(
            LocalExchanger exchanger,
            Consumer<LocalExchangeSink> onFinish)
    {
        this.exchanger = requireNonNull(exchanger, "exchanger is null");
        this.onFinish = requireNonNull(onFinish, "onFinish is null");
    }