suppose we have a mixin:
whose action "$$" is published.
What already works is that this will be published as an action "touch" on the mixed-in domain object.
However, if we try to do this programmatically via the WrapperFactory, ie
then the target that is published is the (transient) mixin object itself, rather than the domain object.
The fix is therefore to make the wrapper factory's wrapper proxy more intelligent, by invoking on the mixed-in action on the mixed-in domain object, rather than simply on the regular default action of the mixin (transient) object.