      - Parameter mediaBrowser: MediaBrowser
      - Parameter index: Int
      */
-    func captionView(for mediaBrowser: MediaBrowser, at index: Int) -> MediaCaptionView?
+    @objc optional func captionView(for mediaBrowser: MediaBrowser, at index: Int) -> MediaCaptionView?
     
     /**
      Optional protocol when need callback

     - Parameter index: Int
     - Parameter mediaBrowser: MediaBrowser
     */
    func didDisplayMedia(at index: Int, in mediaBrowser: MediaBrowser)
    
    /**
     Optional protocol when need callback about action button

     - Parameter index: Int
     - Parameter mediaBrowser: MediaBrowser
     */
    @objc optional func mediaDid(selected: Bool, at index: Int, in mediaBrowser: MediaBrowser)
    
    
    /**
