At least Identifiable as of 0.7 behaves like a Functional Interface from Java 8 on.
A few other similar interfaces like "Nameable", etc. shall be created in Agorava Core API. Allowing Lambda support where Agorava is used with Java 8 or above. The formal annotation @FunctionalInterface is not necessary, but the interface shall be recognized as such by the Java compiler.
As it is not used by many parts of the API yet, Identifiable should also be relocated to the new function package.