public ThumbnailGalleryItemFactory(GetThumbnailLoader getLoader)
        {
            _synchronizationContext = SynchronizationContext.Current;
            if (_synchronizationContext == null)
            {
                throw new InvalidOperationException("It is expected that the factory will be instantiated on and accessed from a UI thread.");
            }

            _getLoader = getLoader;
        }
 public ThumbnailGalleryItemFactory(GetThumbnailLoader getLoader)
     : this(getLoader, false)
 {
 }