function fullResponse() {
    function restifyResponseHeaders(req, res, next) {
        res.once('header', function onceHeader() {
            // Restify 1.0 compatibility
            if (res.defaultResponseFormatters) {
                res.defaultResponseFormatters(res._data);
            }

            res.emit('beforeSend', res._data, res._body);

            // end backwards-compatibility
            return setHeaders(req, res);
        });

        return next();
    }

    return restifyResponseHeaders;
}
handles disappeared CORS headers.
https://github.com/restify/node-restify/issues/284

@public
@function fullResponse
@returns  {Function} Handler