def test_honorsAcceptableCiphersArgument(self):
        """
        If acceptable ciphers are passed, they are used.
        """
        @implementer(interfaces.IAcceptableCiphers)
        class FakeAcceptableCiphers(object):
            def selectCiphers(self, _):
                return [sslverify.OpenSSLCipher(u'sentinel')]

        opts = sslverify.OpenSSLCertificateOptions(
            privateKey=self.sKey,
            certificate=self.sCert,
            acceptableCiphers=FakeAcceptableCiphers(),
        )
        opts._contextFactory = FakeContext
        ctx = opts.getContext()
        self.assertEqual(b'sentinel', ctx._cipherList)

        If acceptable ciphers are passed, they are used.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_sslverify.py