def test_status(self):
        """
        The response status passed to the I{start_response} callable is written
        as the status of the response to the request.
        """
        channel = DummyChannel()

        def applicationFactory():
            def application(environ, startResponse):
                startResponse('107 Strange message', [])
                return iter(())
            return application

        d, requestFactory = self.requestFactoryFactory()
        def cbRendered(ignored):
            self.assertTrue(
                channel.transport.written.getvalue().startswith(
                    b'HTTP/1.1 107 Strange message'))
        d.addCallback(cbRendered)

        self.lowLevelRender(
            requestFactory, applicationFactory,
            lambda: channel, 'GET', '1.1', [], [''], None, [])

        return d

        The response status passed to the I{start_response} callable is written
        as the status of the response to the request.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_wsgi.py