I have already posted idle_dev mailing list (and, no one replied :P).

I think, Ezio's suggestion is good if we will work for Python2.
Using unittest.mock and mock to support Python2 and Python3.
My proposal for GSoC is here.
Making very initial version for Python2 and Python3 and,
 complete Python3 version and, backport it in the end.
I'll set backporting for Python2 as optional work.
My main goal is to make unittest for Python3.