@Override
        public void signalComplete() {
            if (!isComplete()) {
                // Add an empty item to the transfer queue.
                lmdbDataStore.queue.complete();
            }
        }
Set to false if we don't want to keep looking through the store.
stroom-query/stroom-query-common/src/main/java/stroom/query/common/v2/LmdbDataStore.java