Im trying to use a controller to set some parameters on my media items. So, I have PartialContentController<MediaData> which I thiought would grab any item that inherited from MediaData. The images render, but the controller is not getting called. How do I tell Optimizely to use this controller?

[TemplateDescriptor(Inherited = true)]
   public class MediaController : PartialContentController<MediaData>
   {
       private readonly UrlResolver UrlResolver;

       public MediaController(UrlResolver urlResolver) => this.UrlResolver = urlResolver;

       public override ActionResult Index(MediaData currentContent)
       {
           switch (currentContent)
           {
               case VideoFile videoFile:
                   var videoViewModel = new VideoFileViewModel
                   {
                       DisplayControls = videoFile.DisplayControls,
                       Autoplay = videoFile.Autoplay,
                       Copyright = videoFile.Copyright
                   };

                   if (PageEditing.PageIsInEditMode)
                   {
                       videoViewModel.VideoLink = this.UrlResolver.GetUrl(videoFile.ContentLink, null,
                           new VirtualPathArguments { ContextMode = ContextMode.Default });
                       videoViewModel.PreviewImage = ContentReference.IsNullOrEmpty(videoFile.PreviewImage)
                           ? string.Empty
                           : this.UrlResolver.GetUrl(videoFile.PreviewImage, null,
                               new VirtualPathArguments { ContextMode = ContextMode.Default });
                   }
                   else
                   {
                       videoViewModel.VideoLink = this.UrlResolver.GetUrl(videoFile.ContentLink);
                       videoViewModel.PreviewImage = ContentReference.IsNullOrEmpty(videoFile.PreviewImage)
                           ? string.Empty
                           : this.UrlResolver.GetUrl(videoFile.PreviewImage);
                   }

                   return PartialView(ViewRenderingConstants.Media.VideoFile, videoViewModel);
               case ImageMediaData image:
                   var imageViewModel = new ImageMediaDataViewModel
                   {
                       Name = image.Name,
                       Description = image.Description,
                       Width = image.Width,
                       Height = image.Height,
                       AlternateText = image.AltText,
                       Title = image.Title
                   };

                   if (PageEditing.PageIsInEditMode)
                   {
                       imageViewModel.ImageLink = this.UrlResolver.GetUrl(image.ContentLink, null,
                           new VirtualPathArguments { ContextMode = ContextMode.Default });
                   }
                   else
                   {
                       imageViewModel.ImageLink = this.UrlResolver.GetUrl(image.ContentLink);
                   }

                   return PartialView(ViewRenderingConstants.Media.ImageMedia, imageViewModel);
               case CustomPdfFile pdfFile:
                   var pdfViewModel = new PdfFileViewModel { Height = pdfFile.Height };

                   if (PageEditing.PageIsInEditMode)
                   {
                       pdfViewModel.PdfLink = this.UrlResolver.GetUrl(pdfFile.ContentLink, null,
                           new VirtualPathArguments { ContextMode = ContextMode.Default });
                   }
                   else
                   {
                       pdfViewModel.PdfLink = this.UrlResolver.GetUrl(pdfFile.ContentLink);
                   }

                   return PartialView(ViewRenderingConstants.Media.Pdf, pdfViewModel);
               default:
                   return PartialView(ViewRenderingConstants.Media.Index, currentContent.GetType().BaseType.Name);
           }
       }
   }