Thanks for your effort!

This generally looks good. A few minor things:

- testMixIntsAndLongs doesn't have any assertions in it.
- "assert" statements should probably be changed to use the failUnlessEqual/assertEqual methods.
- I'm wary of your assertLastCallWas system; I'd feel more comfortable if you were making assertions about the entire call chain, not just its last item. Also, something like callLst feels strange as a global. Feel free to contact me to discuss this off-list.