@SuppressWarnings("unchecked")
    @Override
    public void setIfUnset(final SerdeGetter getter) {
        if (leftSerializer == null) {
            leftSerializer = (Serializer<V1>) getter.valueSerde().serializer();
        }

        if (rightSerializer == null) {
            rightSerializer = (Serializer<V2>) getter.valueSerde().serializer();
        }

        initNullableSerializer(leftSerializer, getter);
        initNullableSerializer(rightSerializer, getter);
    }
Serializes a {@link LeftOrRightValue}. The serialized bytes starts with a byte that references
to whether the value is V1 or V2.
streams/src/main/java/org/apache/kafka/streams/state/internals/LeftOrRightValueSerializer.java