DeprecationWarning: It is deprecated to return a value that is not None from a test cas #152
Description
Since Python 3.11, tests & coverage will warn:
/opt/hostedtoolcache/Python/3.12.2/x64/lib/python3.12/unittest/case.py:690: DeprecationWarning: It is deprecated to return a value that is not None from a test case (<bound method TestPoFile.test_save_as_mofile of <__main__.TestPoFile testMethod=test_save_as_mofile>>)
return self.run(*args, **kwds)