def test_passesResolverFactory(self):
        """
        L{root.bootstrap} accepts a C{resolverFactory} argument which is passed
        as an argument to L{root.Resolver} when it has successfully looked up
        root hints.
        """
        stubResolver = StubResolver()
        deferredResolver = root.bootstrap(
            stubResolver, resolverFactory=raisingResolverFactory)

        for d in stubResolver.pendingResults:
            d.callback('192.0.2.101')

        self.assertIs(
            deferredResolver._resolverFactory, raisingResolverFactory)

        L{root.bootstrap} accepts a C{resolverFactory} argument which is passed
        as an argument to L{root.Resolver} when it has successfully looked up
        root hints.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_rootresolve.py