def test_simplifier(self):
        """
        L{ComplexResolverSimplifier} translates an L{IHostnameResolver} into an
        L{IResolverSimple} for applications that still expect the old
        interfaces to be in place.
        """
        self.pool, self.doThreadWork = deterministicPool()
        self.reactor, self.doReactorWork = deterministicReactorThreads()
        self.getter = FakeAddrInfoGetter()
        self.resolver = GAIResolver(self.reactor, lambda: self.pool,
                                    self.getter.getaddrinfo)
        simpleResolver = ComplexResolverSimplifier(self.resolver)
        self.getter.addResultForHost('example.com', ('192.168.3.4', 4321))
        success = simpleResolver.getHostByName('example.com')
        failure = simpleResolver.getHostByName('nx.example.com')
        self.doThreadWork()
        self.doReactorWork()
        self.doThreadWork()
        self.doReactorWork()
        self.assertEqual(self.failureResultOf(failure).type, DNSLookupError)
        self.assertEqual(self.successResultOf(success), '192.168.3.4')

        L{ComplexResolverSimplifier} translates an L{IHostnameResolver} into an
        L{IResolverSimple} for applications that still expect the old
        interfaces to be in place.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_resolver.py