The idea for this work is to specify mocked method arguments in a more flexible way. It was actually surprisingly trivial to implement. I'll be writing a more detailed post in the future explaining what these changes mean to a user of mock4as.
I also took the opportunity to experiment with using git and github, so the changes are available to all and sundry as a github repository. I will be talking to the mock4as guys about getting my changes merged into the official mock4as codebase