public IEnumerable <IMultimedia> MultimediasOf(long id)
        {
            IEnumerable <Picture> pictures = resourcesService.PicturesOf(id.ToString());
            IEnumerable <Video>   videos   = resourcesService.VideosOf(id.ToString());

            List <IMultimedia> multimedias = new List <IMultimedia>();
            int order = 0;

            foreach (Picture picture in pictures)
            {
                multimedias.Add(new Multimedia(picture.Title, order++, picture.Url, MultimediaType.Image));
            }

            foreach (Video video in videos)
            {
                multimedias.Add(new Multimedia(video.Title, order++, video.Url, MultimediaType.Video));
            }

            return(multimedias);
        }