Include a cononical example of setup in docs.

[nicklockwood]

Include a cononical example of setup in docs.

[nicklockwood]

setUp is BaseModel's designated constructor (kind of). setUp is always called, regardless of how your BaseModel is created, so it's a reliable way to initialise your model's properties.

It's optional, and if you do implement it, you don't need to call [super setUp].

If you already implement one or more of the other setWithX methods then you probably don't need to implement setUp.

As an example of how it's used, I use it in the TodoList Example in the TodoList model to create an empty mutable array of items before loading the content. I could create the array in the setWithArray: method instead, but this way I could delete the TodoList.plist if I wanted and the model would still function correctly, it just wouldn't have any default data.

Hope that helps.