             let currentTag = cell.tag + 1
             cell.tag = currentTag
             
-            let asset = self.assetsFetchResults[indexPath.item] as! PHAsset
+            let asset = self.assetsFetchResults![indexPath.item] as! PHAsset
             
             let imageRequestOptions = PHImageRequestOptions()
             imageRequestOptions.networkAccessAllowed = true

    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
        switch indexPath.section {
        case self.recentPhotosSection:
            let asset = self.assetsFetchResults[indexPath.item] as! PHAsset
            
            let itemCellHeight = (collectionViewLayout as! UICollectionViewFlowLayout).itemSize.height
            

    var delegate: RecentPhotosCollectionViewControllerDelegate?
    
    private var selectedAssets: [PHAsset] {
        return (self.collectionView?.indexPathsForSelectedItems() as? [NSIndexPath])?.map({ self.assetsFetchResults![$0.item] as! PHAsset }) ?? []
    }
    
    private var assetsFetchResults: PHFetchResult?
    private let maxFetchResultsCount = 70
    private let imageManager = PHCachingImageManager()
    private var cachingImageThumbnailSize = CGSizeZero
