The subsystem and core-model tests should be expanded to test FULL models. In many cases these tests do not use a full xml. We should generate a full xml file for testing, possibly by using the schema. Or by inspecting the resource registrations a bit similar to the ExpressionSupportTestCase.

We might need something to deal with the case where e.g. a parent expects only one of two children to be set (i.e. there is a choice) and not both. In those cases it would be good to be able to test all possible permutations. This testing should be at least the parsing and marshalling of the main model. It is uncertain whether it will be possible to do do transformers, although perhaps we could do something like the DomainAdjusters from the mixed domain tests.