def test_tlsv1ByDefault(self):
        """
        L{sslverify.OpenSSLCertificateOptions} will make the default minimum
        TLS version v1.0, if no C{method}, or C{insecurelyLowerMinimumTo} is
        given.
        """
        opts = sslverify.OpenSSLCertificateOptions(
            privateKey=self.sKey,
            certificate=self.sCert
        )
        opts._contextFactory = FakeContext
        ctx = opts.getContext()
        options = (SSL.OP_NO_SSLv2 | SSL.OP_NO_COMPRESSION |
                   SSL.OP_CIPHER_SERVER_PREFERENCE | SSL.OP_NO_SSLv3)
        self.assertEqual(options, ctx._options & options)

        L{sslverify.OpenSSLCertificateOptions} will make the default minimum
        TLS version v1.0, if no C{method}, or C{insecurelyLowerMinimumTo} is
        given.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_sslverify.py