Hi folks. I was reading the PBE chapter about reflection where it talks a little about Method Wrappers. Then, I took a look at TestCoverage implementation. After that, I took a look at http://www.squeaksource.com/ObjectsAsMethodsWrap The main difference between both approaches are: TestCoverage - Just extends from ProtoObject, implement doesNotUnderstand: , run: aSelector with: anArray in: aReceiver , etc - To install and uninstall the wrappers uses methodDictionary at: xxx put: yyy - Just for test coverage. ObjectAsMethodWrapper - Is more generic, support pre and post closures, and you can subclass and create you own wrapper - To install and uninstall the wrappers it uses Class >> addSelector: self selector withMethod: self So...what I did ?? I created a TestCoverage but creating a subclass of ObjectAsMethodWrapper called TestCoverageMethodWrapper which just implements a 1 or 2 methods. I mean, I reused the generic ObjectAsMethodWrapper. It seems to work ok. I did some test running TestCoverage with both implementation and it seems mine (TestCoverageMethodWrapper) is 30% much slower than the original. Trying to understand why, I think it is because the original one uses just methodDictionary at: xxx put: yyy but mine uses Class >> addSelector: self selector withMethod: self. In this last method, there are all the notifications, add to localSelectors...etc Now...I have two questions: 1) For a generic approach to method wrappers, which of those two ways would you use ? should I care about notifying, adding to localSelectors, etc? Or at is just temporal, I don't care ? which are the pros and cons you see with each alternative ? 2) Do you think it make sense to the package ObjectsAsMethodsWrap in PharoCore as a "library" to create lightweight proxies ? It is just 4 classes and it would be cool to change TestCoverage to that implementation. Then, you only don't have the library, but also some real examples. Of course, this can be done if we eleiminate the 30% of slowleness. so...what do you think ? Cheers Mariano