Currently the metadata bridges are setup within the BeanContainer (BeanContainer.initialize). This makes it impossible to add new metadata bridges (ex: for singleton container concurrency management).

Instead of hardcoding the metadata bridges within the BeanContainer, it would be more flexible to allow the EJBContainer to return the AnnotationRepositoryToMetadata with appropriate metadata bridges setup. This way the common metadata bridge setup can be done within EJBContainer and any additional metadata bridges can then be setup through overridden method in individual containers. The BeanContainer while initializing the advisor can then just ask the EJBContainer for the AnnotationRepositoryToMetadata.