test_guess_all_types(): Use a more robust test for checking that
guess_all_extensions() returns (at least) what we expect.  As Jeff
Epler suggests in

http://mail.python.org/pipermail/python-dev/2003-September/038264.html

We use a set to test the results.  This fixes the test when
test_urllib2 is run before test_mimetypes.
1 file changed