Qt constant QNetworkCookieJar

In my Qt application, I need to save cookies between different program launches.

I read that QNetworkCookieJar for some reason does not support persistent cookie storage; the manual says that I should basically do it myself.

I understand that writing a simple class like this is not very difficult, but it seems like reimagining the wheel of the worst degree, since for sure someone needed it before.

So my question basically is why Qt doesn't add persistent storage support to the default implementation? And is there a QNetworkCookieJar class somewhere on the Internet that has ongoing support for cookies?