def createServer(self, address, portNumber, factory):
        """
        Create an SSL server with a certificate using L{IReactorSSL.listenSSL}.
        """
        cert = ssl.PrivateCertificate.loadPEM(FilePath(certPath).getContent())
        contextFactory = cert.options()
        return reactor.listenSSL(
            portNumber, factory, contextFactory, interface=address)

        Create an SSL server with a certificate using L{IReactorSSL.listenSSL}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_ssl.py