forked from loafle/openapi-generator-original
`TestCase.assertDictContainsSubset()` was deprecated in Python 3.2, which went EOL in 2016. Rewrite the assertion to target Python 3.8+. See: https://docs.python.org/3.2/library/unittest.html#unittest.TestCase.assertDictContainsSubset See: https://devguide.python.org/versions/