final GsonBuilder builder = new GsonBuilder().serializeNulls();
// Register a type adapter for the HavaloUUID entity type.
builder.registerTypeAdapter(new TypeToken<HavaloUUID>(){}.getType(),
new HavaloUUID.HavaloUUIDTypeAdapter());
builder.registerTypeAdapter(new TypeToken<Date>(){}.getType(),
new KolichDefaultDateTypeAdapter(iso8601Format__));
builder.registerTypeAdapter(new TypeToken<File>(){}.getType(),
new Repository.FileTypeAdapter());
builder.registerTypeAdapter(new TypeToken<Trie<String, HashedFileObject>>(){}.getType(),
new Repository.TrieTypeAdapter());
builder.registerTypeAdapter(new TypeToken<Exception>(){}.getType(),