}
private Sorter<IdAndVersion> createSorter(IdAndVersionFactory factory) {
SortConfig sortConfig = new SortConfig().withMaxMemoryUsage(DEFAULT_SORT_MEM);
DataReaderFactory<IdAndVersion> dataReaderFactory = new IdAndVersionDataReaderFactory(factory);
DataWriterFactory<IdAndVersion> dataWriterFactory = new IdAndVersionDataWriterFactory();
return new Sorter<IdAndVersion>(sortConfig, dataReaderFactory, dataWriterFactory,
new NaturalComparator<IdAndVersion>());
}