def testSSLTransportConsideredSecure(self):
        """
        If a server doesn't offer APOP but the transport is secured using
        SSL or TLS, a plaintext login should be allowed, not rejected with
        an InsecureAuthenticationDisallowed exception.
        """
        p, t = setUp(greet=False)
        directlyProvides(t, interfaces.ISSLTransport)
        p.dataReceived(b"+OK Howdy\r\n")
        d = p.login(b"username", b"password")
        self.assertEqual(t.value(), b"USER username\r\n")
        t.clear()
        p.dataReceived(b"+OK\r\n")
        self.assertEqual(t.value(), b"PASS password\r\n")
        p.dataReceived(b"+OK\r\n")
        return d

        If a server doesn't offer APOP but the transport is secured using
        SSL or TLS, a plaintext login should be allowed, not rejected with
        an InsecureAuthenticationDisallowed exception.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_pop3client.py