code: public static ObjectMapper configure(ObjectMapper objectMapper) {
          objectMapper.registerModule(INSTANCE);
          objectMapper.setHandlerInstantiator(new MongoJacksonHandlerInstantiator(
                  new MongoAnnotationIntrospector(objectMapper.getDeserializationConfig())));
          return objectMapper;
      }
docs: Configure the given object mapper to be used with the Mongo Jackson Mapper.  Please call this method rather than
  calling objectMapper.with(MongoJacksonMapperModule.INSTANCE), because Jacksons module system doesn't allow the
  mongo jackson mapper to do all the configuration it needs to do.  This method will do that configuration though.
  
  @param objectMapper The object mapper to configure
  @return This object mapper (for chaining)