@Override
        public DataList<DATATYPE> get(long timeout, TimeUnit timeUnit) throws InterruptedException, ExecutionException, TimeoutException {
            return drain(owner.incoming().completedFuture().get(timeout, timeUnit));
        }
Wait until all data is available.
When and if this returns normally all data is available in the returned data list
container-core/src/main/java/com/yahoo/processing/response/AbstractDataList.java