I'm writing a generic 'attribute/key editor' view class on iOS, and it checks the type of the editing key using `[objectForKey isKindOfClass:[NSDate class]]`, for example. I just ran into a wall when I realized that will fail if `objectForKey` is `nil`. Is there a way to get the class/return type for a generic Objective-C property, even if said property is `nil`? I know about `method_getReturnType` in the Objective-C run-time, but that sounds like overkill for what I need.