def test_renderWithUnknownHostNoDefault(self):
        """
        L{NameVirtualHost.render} returns a response with a status of I{NOT
        FOUND} if the instance's C{default} is L{None} and there is no host
        matching the value of the I{Host} header in the request.
        """
        virtualHostResource = NameVirtualHost()
        request = DummyRequest([''])
        request.requestHeaders.addRawHeader(b'host', b'example.com')
        d = _render(virtualHostResource, request)
        def cbRendered(ignored):
            self.assertEqual(request.responseCode, NOT_FOUND)
        d.addCallback(cbRendered)
        return d

        L{NameVirtualHost.render} returns a response with a status of I{NOT
        FOUND} if the instance's C{default} is L{None} and there is no host
        matching the value of the I{Host} header in the request.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_vhost.py