def test_singleUseKeys(self):
        """
        If C{singleUseKeys} is set, every context must have
        C{OP_SINGLE_DH_USE} and C{OP_SINGLE_ECDH_USE} set.
        """
        opts = sslverify.OpenSSLCertificateOptions(
            privateKey=self.sKey,
            certificate=self.sCert,
            enableSingleUseKeys=True,
        )
        opts._contextFactory = FakeContext
        ctx = opts.getContext()
        options = SSL.OP_SINGLE_DH_USE | SSL.OP_SINGLE_ECDH_USE
        self.assertEqual(options, ctx._options & options)

        If C{singleUseKeys} is set, every context must have
        C{OP_SINGLE_DH_USE} and C{OP_SINGLE_ECDH_USE} set.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_sslverify.py