[Qt-interest] Proxy model with more indexes than its sourcemodel

[Duane Hebert]

>Ahh you're right, I was thinking that it was virtual in QAbstractItemModel but not in QAbstractProxyModel. My inexperience with C++ 
>is showing...

If it's virtual in the base class, it's virtual in the derived class.  You don't need to add the virtual
tag in a derived class but most people do so anyway to document this.