def test_unTLS(self):
        """
        Test for server startTLS not followed by a startTLS in client: the data
        received after server startTLS should be received as raw.
        """
        def check(ignored):
            self.assertEqual(
                self.serverFactory.lines,
                UnintelligentProtocol.pretext
            )
            self.assertTrue(self.serverFactory.rawdata,
                            "No encrypted bytes received")
        d = self._runTest(UnintelligentProtocol(),
                          LineCollector(False, self.fillBuffer))
        return d.addCallback(check)

        Test for server startTLS not followed by a startTLS in client: the data
        received after server startTLS should be received as raw.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_ssl.py