@Override
 public List<BeanPropertyWriter> changeProperties(
     SerializationConfig config,
     BeanDescription beanDesc,
     List<BeanPropertyWriter> beanProperties) {
   for (int i = 0; i < beanProperties.size(); ++i) {
     final BeanPropertyWriter writer = beanProperties.get(i);
     if (Optional.class.isAssignableFrom(writer.getPropertyType())) {
       beanProperties.set(i, new GuavaOptionalBeanPropertyWriter(writer));
     }
   }
   return beanProperties;
 }