* When `SKZoomingScrollView` is initialized, the `setup()` method is called twice: once in `init(frame:)` and then once more in `init(frame:browser:)`
* Double call of `setup()` results in UI elements (such as `SKDetectingImageView`) created twice
* Even though `SKZoomingScrollView`’s properties (e.g. `imageView`) are reassigned on the second call of `setup()`, the UI elements remain in the view hierarchy and device’s memory
* To fix this, `init(frame:browser:)` has been to changed to be a designated initializer, and `init(frame:)` has been removed

…ialization