The current Hibernate cartridge will not allow any associations to model elements that are not being generated by AndroMDA. This makes it difficult to have a UML model which models the real system being developed where AndroMDA generates the J2EE components.
For instance, any dependency is treated as a use of an exception class. It should at least check the other end, and if it is not an exception, do not add the dependency to the metafacade, or ignore it. Currently, an exception is thrown while calling something like "isExceptions".
For other associations, like aggregation of entities by other classes which are not themselves entities or other J2EE components, the model validation is requiring public visibility. That is not too bad, but I am not sure how much more is going to happen if the code had been successfully generated.
The main point is to make certain that other model elements can co-exist with the subset of model elements that are generated by AndroMDA cartridges. This probably is not limited to the Hibernate cartridge.