Creates SSLContext instance for usage in asyncio.create_server.
        See ssl.SSLSocket.__init__ for more details.

def _create_ssl_context(cfg):
        """ Creates SSLContext instance for usage in asyncio.create_server.
        See ssl.SSLSocket.__init__ for more details.
        """
        ctx = ssl.SSLContext(cfg.ssl_version)
        ctx.load_cert_chain(cfg.certfile, cfg.keyfile)
        ctx.verify_mode = cfg.cert_reqs
        if cfg.ca_certs:
            ctx.load_verify_locations(cfg.ca_certs)
        if cfg.ciphers:
            ctx.set_ciphers(cfg.ciphers)
        return ctx