     
     static var itemsRatioCache = [Int : CGFloat]()
 
+    static func clearCache() {
+        itemsRatioCache.removeAll(keepCapacity: false)
+    }
+    
     static func itemSizeForType(type: BRNImagePickerSheetItemSize, asset: ALAsset?, indexPath: NSIndexPath?) -> CGSize {
         var ratio: CGFloat = 1.0
 

                        if result == nil {
                            return
                        }
                        
                        self.assets.append(result);
                        self.photosCache.addObject(NSNull())
                    })
                    
                } else {


    static func ratioForAsset(asset: ALAsset?, indexPath: NSIndexPath) -> CGFloat {

       
        if let ratio = itemsRatioCache[indexPath.section] {
            return ratio
        }
