Hi, What's the best way of determining if a certain feature is available? I know you can check whether certain methods of a class exist, but that requires the class itself to exist, does it not? How can I determine if that class exists? Right now, I'm thinking I'll try using gestaltSystemVersionMinor, but there's a pretty clear note in the documentation against doing that: Specifically, I'm wondering about (User) Notification Center. If it's available, I'd like to use it; if it's not available, I'd like to fall back on alert windows.