@SuppressWarnings("WeakerAccess")
    public Serde<?> defaultValueSerde() {
        final Object valueSerdeConfigSetting = get(DEFAULT_VALUE_SERDE_CLASS_CONFIG);
        if (valueSerdeConfigSetting == null) {
            throw new ConfigException("Please specify a value serde or set one through StreamsConfig#DEFAULT_VALUE_SERDE_CLASS_CONFIG");
        }
        try {
            final Serde<?> serde = getConfiguredInstance(DEFAULT_VALUE_SERDE_CLASS_CONFIG, Serde.class);
            serde.configure(originals(), false);
            return serde;
        } catch (final Exception e) {
            throw new StreamsException(
                String.format("Failed to configure value serde %s", valueSerdeConfigSetting), e);
        }
    }
Return an {@link Serde#configure(Map, boolean) configured} instance of {@link #DEFAULT_VALUE_SERDE_CLASS_CONFIG value
Serde class}.

@return an configured instance of value Serde class
streams/src/main/java/org/apache/kafka/streams/StreamsConfig.java