Hi Frank
Since you are present in the Pharo mailing-list, may be you want to send the code to get it 
included into pharo, please do it?

(Squeak trunk now lets you create methods not just on an MNU but also
where people have things like "self subclassResponsibility", "self
notYetImplemented" or "self shouldBeImplemented" flags such that you
can debug-edit-and-continue.)

Stef