def test_cacheOverride(self):
        """
        L{server.DNSServerFactory.__init__} assigns the last object in the
        C{caches} list to L{server.DNSServerFactory.cache}.
        """
        dummyResolver = object()
        self.assertEqual(
            server.DNSServerFactory(caches=[object(), dummyResolver]).cache,
            dummyResolver)

        L{server.DNSServerFactory.__init__} assigns the last object in the
        C{caches} list to L{server.DNSServerFactory.cache}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_server.py