Just to open up a discussion: I'm all for removing these kinds of imports for the actual app, but maybe it isn't safe to assume that people are going to have `Foundation` in their prefix when using our library? Or maybe they aren't using a prefix at all? It's probably safer with `UIKit` and `Foundation` since they are the defaults, and if people go out of their way to remove them, they _probably_ know what they're doing. but we should take this into consideration.2