Scroll UICollectionView to bottom

Question

I would like to scroll the UICollectionView to the bottom so the last item is in the view. I have tried to use scrollToItemAtIndexPath but it does not seem to be working. I want

Answer 1

Updated for Swift 3:

let item = self.collectionView(self.collectionView!, numberOfItemsInSection: 0) - 1
let lastItemIndex = IndexPath(item: item, section: 0)
collectionView?.scrollToItem(at: lastItemIndex, at: UICollectionViewScrollPosition.top, animated: true)