The Build Compatible Extension API has a method ObserverInfo.bean() that provides access to the bean that declares given observer. The Portable Extension API only has ObserverMethod.getBeanClass() (providing access to the class that declares given observer).

To keep BCExtensions a strict subset of PExtensions, either we have to remove ObserverInfo.bean(), or add ObserverMethod.getDeclaringBean() (copying the name from Weld's ObserverMethodImpl, which does expose the declaring bean).