IntPackedSectorMap entry type, with custom read function.regionFactory and maxCacheSizeK such that key.getRegionKey().equals(regionKey) && key.getId() == id, or throws
IllegalArgumentException when the region key and id pair doesn't represent any key of this type.IKeyProvider.getKeyCount(RegionKey).IHeaderDataEntry objects by IKey, and provides the necessary metadata (currently entry size)RegionKey),
and logical location inside the region (ID).regionFactory and maxCacheSizeByteBuffer.