JavaDoc and reference docs now warn developers against interacting with
bean instances within BeanFactoryPostProcessor implementations in order
to avoid premature bean instantiation.
See SPR-7450 for an example of a third-party BFPP
(OAuthTokenLifecycleRegistryPostProcessor) prematurely instantiating
a FactoryBean instance, such that bean post-processing is bypassed
and autowired injection (via @Inject) never occurs.