iOS 10 App Development Essentials was published on October 21, 2016. The current revision is 1.0. The revision of your copy of the book can be found in the copyright page at the start of the book.
Section 35.2 - Adding the Image Files
The steps in this section state the image file names in the incorrect order. The image named firstname.lastname@example.org should be dropped onto the 2x placeholder, while the email@example.com image should be dropped onto the 2x Compact Width placeholder.
Section 41.5 - 41.5 Implementing the metadataQueryDidFinishGathering Method
The code for the completed metadataQueryDidFinishGathering method at listed the end of this section contains the following redundant line of code which can be removed:
let resultURL = query.value(ofAttribute: NSMetadataItemURLKey, forResultAt: 0) as! URL
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