@Override
            public BiConsumer<List<T>, T> accumulator() {
                return (accumulator, item) -> {
                    if (pageRequest == null
                            || (
                            counter >= pageRequest.getOffset()
                                    && accumulator.size() < pageRequest.getLength())) {

                        accumulator.add(item);
                    }
                    counter++;
                };
            }
Used for filter queries (maybe bounded).
stroom-util/src/main/java/stroom/util/ResultPageFactory.java