Can not send the notification from the Notifications class since that class is registered in the test-context and for some reason HSQLDB fails with some unknown check constraint violation with absolutely no information about why.
For some reason it is not possible to debug HSQLDB with breakpoints to step through and see exactly why it fails, so registering a new single purpose class in the cross-cutting module (that's not available in test) is used as a work-around.