Hi, Just a question regarding this example I would like to teach (PBE p. 298). The code: | class | class := Collection. SystemNavigation default browseMessageList: (class withAllSubclasses gather: [:each | each methodDict associations select: [:assoc | assoc value sendsToSuper] thenCollect: [:assoc | MethodReference class: each selector: assoc key]]) name: 'Supersends of ' , class name , ' and its subclasses' does not work in current Pharo. I did the following, after browsing the system a little bit. First I changed 'MethodReference' for 'RGMethodDefinition' and defined a new method 'Object class >> realClass ^self' (this is because the system complained that 'Array class' did not understand 'realClass') Now it works, but I do not really understand why. My questions are: a) Is there a canonical way of doing what was usually done with 'MethodReference'? (I do not think that substituting 'MethodReference' for 'RGMethodDefinition' is the right answer) b) What is the 'Ring'? (besides an evil organization from the show 'Chuck' :)) Thanks in advance, Bests, Jordi PS: I know I am being lazy, ok? I am still getting to grips with current Pharo after more than one year without using it. I am working on it... Any help will be really appreciated.