There is currently no test_mailcap or any other standalone unit test for
the mailcap module. The only existing test is a self-test at the end of
the module.

I would like to be assigned to work on this patch.

(Why am I assigning myself to write tests for a small, older module? I'm
a complete noob to the Python-Dev community and I'm getting my feet wet
with this. Let me know if you have any advice or if I'm doing something
wrong.)