def test_decodeRaises(self):
        """
        Resource traversal which enouncters an L{HTTPAuthSessionWrapper}
        results in an L{UnauthorizedResource} when the request has a I{Basic
        Authorization} header which cannot be decoded using base64.
        """
        self.credentialFactories.append(BasicCredentialFactory('example.com'))
        request = self.makeRequest([self.childName])
        request.requestHeaders.addRawHeader(b'authorization', b'Basic decode should fail')
        child = getChildForRequest(self.wrapper, request)
        self.assertIsInstance(child, UnauthorizedResource)

        Resource traversal which enouncters an L{HTTPAuthSessionWrapper}
        results in an L{UnauthorizedResource} when the request has a I{Basic
        Authorization} header which cannot be decoded using base64.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_httpauth.py