Spring has a unique feature: BeanPostProcessor. It is used to auto-magically apply proxies to any qualified non-infrastructure beans.

Spring's autoproxy facilities are built on top of BeanPostProcessor.

This feature is sometimes useful because it could reduce the amount of configuration work. One does not need to explicitly specify FactoryBeans in order to get a bean proxied.

I did not find a corresponding facility in Pico/Nano. So I'll just assume that Pico/Nano don't support it.

Yan/Nuts has no support for this feature currently. Nuts' custom tag can be used instead to reduce configuration code size.