anchor.diff:  This approach simplifies container instantiation, as only one class needs to be dealt
   with, rather than requiring the developer to remember a potentially large number of
   `@Configuration` classes during construction.
  +
  +[TIP]
  +====
  +As of Spring Framework 4.2, `@Import` also supports references to regular component
  +classes, analogous to the `AnnotationConfigApplicationContext.register` method.
  +This is particularly useful if you'd like to avoid component scanning, using a few
  +configuration classes as entry points for explicitly defining all your components.
  +====
   
   [[beans-java-injecting-imported-beans]]
   ===== Injecting dependencies on imported @Bean definitions
  
positive.code: about singletons here.
  ====
  
  [NOTE]
  ====
  There are a few restrictions due to the fact that CGLIB dynamically adds features at
  startup-time:
  
  * Configuration classes should not be final
  * They should have a constructor with no arguments
  ====
  
  
  
negative.code: 
  [TIP]
  ====
  The JSR-250 `@PostConstruct` and `@PreDestroy` annotations are generally considered best
  practice for receiving lifecycle callbacks in a modern Spring application. Using these
  annotations means that your beans are not coupled to Spring specific interfaces. For
  