 
 }
 
-internal protocol DKPhotoGalleryContentDelegate {
+internal protocol DKPhotoGalleryContentDelegate: class {
     
     func contentVCCanScrollToPreviousOrNext(_ contentVC: DKPhotoGalleryContentVC) -> Bool
     

        self.updateFooterView()
        
        if self.dataSource.hasIncrementalDataForLeft() {
            self.leftIncrementalIndicator = DKPhotoIncrementalIndicator.indicator(with: .left) {
                self.dataSource.incrementalItemsForLeft { [weak self] (count) in
                    guard let strongSelf = self, let leftIncrementalIndicator = strongSelf.leftIncrementalIndicator else { return }
                    
                    let scrollView = strongSelf.mainView

@objc
open class DKPhotoGalleryContentVC: UIViewController, UIScrollViewDelegate {
    
    internal weak var dataSource: DKPhotoGalleryContentDataSource!
    internal weak var delegate: DKPhotoGalleryContentDelegate?
    
    public var pageChangeBlock: ((_ index: Int) -> Void)?
    public var prepareToShow: ((_ previewVC: DKPhotoBasePreviewVC) -> Void)?
