def test_tlsProtocolsAllModernTLS(self):
        """
        When calling L{sslverify.OpenSSLCertificateOptions} with
        C{insecurelyLowerMinimumTo} set to TLSv1.0 and
        C{lowerMaximumSecurityTo} to TLSv1.2, it will exclude both SSLs and
        the (unreleased) TLSv1.3.
        """
        opts = sslverify.OpenSSLCertificateOptions(
            privateKey=self.sKey,
            certificate=self.sCert,
            insecurelyLowerMinimumTo=sslverify.TLSVersion.TLSv1_0,
            lowerMaximumSecurityTo=sslverify.TLSVersion.TLSv1_2,
        )
        opts._contextFactory = FakeContext
        ctx = opts.getContext()
        options = (SSL.OP_NO_SSLv2 | SSL.OP_NO_COMPRESSION |
                   SSL.OP_CIPHER_SERVER_PREFERENCE | SSL.OP_NO_SSLv3 |
                   opts._OP_NO_TLSv1_3)
        self.assertEqual(options, ctx._options & options)

        When calling L{sslverify.OpenSSLCertificateOptions} with
        C{insecurelyLowerMinimumTo} set to TLSv1.0 and
        C{lowerMaximumSecurityTo} to TLSv1.2, it will exclude both SSLs and
        the (unreleased) TLSv1.3.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_sslverify.py