class CookieManager {
	getCookie(string url) {
		...
	}
	putCookie(... cookie) {
		...
	}
}

class MyCookieManager extends CookieManager {
	List<Cookie> cookies = new List<Cookie>();

	override putCookie(... cookie) {
		base.putCookie(... cookie); // This is calling the parent class's method
		cookies.add(cookie);
	}
}

// So now in the MyCookieManager's cookies field you can reach all the cookies. You won't have to use the getCookie(string url) parameter.