     }
 
     func shelfView(shelfView: Shelf.View, heightForSection section: Int) -> CGFloat {
-        return CGFloat(120)
+        return 120
     }
 
     func shelfView(shelfView: Shelf.View, numberOfItemsInSection section: Int) -> Int {

    }

    func shelfView(shelfView: Shelf.View, widthFotItemAtIndexPath indexPath: NSIndexPath) -> CGFloat {
        return 100
    }

}

        let frame = view.bounds

        let shelfView = Shelf.View(frame: frame)
        shelfView.dataSource = self
        shelfView.delegate = self
        shelfView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "cell")
