final Pair pair = (Pair) msg;
final Iterator itty = (Iterator) pair.getValue1();
final RequestMessage requestMessage = (RequestMessage) pair.getValue0();
// the batch size can be overriden by the request
final int resultIterationBatchSize = (Integer) requestMessage.optionalArgs(Tokens.ARGS_BATCH_SIZE).orElse(settings.resultIterationBatchSize);
// timer for the total serialization time
final StopWatch stopWatch = new StopWatch();
final EventExecutorGroup executorService = ctx.executor();