Swift: Loading Images Asynchronously and storing with NSCache and NSURLCache

my review point is 9/10

https://youtu.be/BIgqHLTZ_a4?t=1m55s   getting image from url ( NSURLSession.sharedSession().dataTaskWithURL )

https://youtu.be/BIgqHLTZ_a4?t=7m18s   개발자가 만들어 사용하는 image caching example

https://youtu.be/BIgqHLTZ_a4?t=10m45s   memory low warning hook ( didReceiveMemoryWarning )

https://youtu.be/BIgqHLTZ_a4?t=11m30s   apple에서 제공하는 NSCache를 이용한 caching 작업

https://youtu.be/BIgqHLTZ_a4?t=13m45s   url작업은 기본 cache 기능이 있는데 이 기준치를 변경하는 방법 ( NSURLCache )

Swift: Facebook News Feed – Dynamic Cell Content

my review point is 8/10

https://youtu.be/L9cZrAbxN1E?t=12m52s   estimate size of cell which depends on length of string

Swift: Create Facebook (Part 2) – UICollectionView, NSLayoutConstraint

my review point is 8/10

https://youtu.be/ZwBYQpLQAvw?t=8m15s   button style ( setTitle, setTitleColor , setImage , titleEdgeInsets)

https://youtu.be/ZwBYQpLQAvw?t=14m35s   equally spaced out elements 

https://youtu.be/ZwBYQpLQAvw?t=18m37s   refresh collection view when user change orientation ( viewWillTransitionToSize , invalidateLayout)