function callback(error, payload)
        {
            var models = [];
            if (!error && payload)
                models = WebInspector.CSSMedia.parseMediaArrayPayload(this, payload);
            userCallback(models);
        }
@param {?Protocol.Error} error
@param {?Array.<!CSSAgent.CSSMedia>} payload
@this {!WebInspector.CSSStyleModel}