def _invalidAuthorizationTest(self, response):
        """
        Create a request with the given value as the value of an
        I{Authorization} header and perform resource traversal with it,
        starting at C{self.wrapper}.  Assert that the result is a 401 response
        code.  Return a L{Deferred} which fires when this is all done.
        """
        self.credentialFactories.append(BasicCredentialFactory('example.com'))
        request = self.makeRequest([self.childName])
        request.requestHeaders.addRawHeader(b'authorization', response)
        child = getChildForRequest(self.wrapper, request)
        d = request.notifyFinish()
        def cbFinished(result):
            self.assertEqual(request.responseCode, 401)
        d.addCallback(cbFinished)
        request.render(child)
        return d

        Create a request with the given value as the value of an
        I{Authorization} header and perform resource traversal with it,
        starting at C{self.wrapper}.  Assert that the result is a 401 response
        code.  Return a L{Deferred} which fires when this is all done.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_httpauth.py