Map<Data, MultiMapWrapper> collections = entry.getValue();
out.writeInt(collections.size());
for (Map.Entry<Data, MultiMapWrapper> collectionEntry : collections.entrySet()) {
Data key = collectionEntry.getKey();
key.writeData(out);
MultiMapWrapper wrapper = collectionEntry.getValue();
Collection<MultiMapRecord> coll = wrapper.getCollection(false);
out.writeInt(coll.size());
String collectionType = MultiMapConfig.ValueCollectionType.SET.name();
if (coll instanceof List) {