title: Adding Multiple NSTextContainers to an NSLayoutManager
body: <p>I notice that you can add multiple text containers to a layout manager in Objective-C using the <code>addTextContainer:(NSTextContainer *)textContainer</code> selector. Using TextKit, I've only ever had to add one text container, and when messing around with multiple text containers, all of the textviews just get filled with the same text from the text storage linked to the layout manager. I'm simply curious, but when would I ever need to add multiple text containers to one layout manager?</p>