I had a working version which also used inspect before I saw your 3.0
version, but they both use inspect similarly, very straightforward. I
seem to recall only one of the version used inspect to get the doc
string, but I don't remember which one...

Depending on how you divide things, this patch includes more than just
two different developments. But they are interrelated to some extent.
And one of the developments is more rigorous testing, which this version
passes with flying colors.

If you wish, I can try to get another developer or two to test and
review this patch, if that will help somehow. Or anything else that will
help...