No documentation of Dune::TestSuite generated

I just noticed that the utility Dune::TestSuite and any other utility from the dune/common/test directory is excluded from doxygen. So, no documentation of these classes is generated. It is excluded in multiple forms (directory is on the exclude list and there is another exclude pattern containing "/test/"). What is the best strategy to add these classes to doxygen? Can we have an exclude from the exclude?