Description
Necessary to override the method itself in the subclass, else
https://github.com/apache/isis/blob/69b4859f27ce857e9af75b7d1ef0ae7b42e5cc2c/core/wrapper/src/main/java/org/apache/isis/core/wrapper/handlers/DomainObjectInvocationHandler.java#L297
does not find the actual ObjectActionMixedIn (the mixin's ObjectActionDefault does not match)