private ConfigurationOptions getConfigurationOptions() { ConfigurationOptions defaults = ConfigurationOptions.defaults(); TypeSerializerCollection serializers = defaults.getSerializers().newChild(); serializers.registerType(TypeToken.of(Duration.class), new DurationSerializer()); //explicit set enum serializer because otherwise they will be interpreted as class with the requirement of //a public constructor TypeSerializer<Enum> enumSerializer = serializers.get(TypeToken.of(Enum.class)); serializers.registerType(TypeToken.of(StorageType.class), enumSerializer); serializers.registerType(TypeToken.of(HashingAlgorithm.class), enumSerializer); return defaults.setSerializers(serializers); }