public PodcastItemViewModel(SyndicationItem item)
{
OriginalUri = item.GetPodcastUris().First();
DatePublished = item.PublishedDate;
Title = item.Title.Text;
string summary = item.Summary.IfNotNull(its => its.Text);
Summary = summary;
Id = new PodcastId(this.GetStorageUrl());
PlayPodcastCommand = ReactiveCommand.Create();
PlayPodcastCommand.Subscribe(OnPlayPodcast);
_cachingState = FileCache.Instance.CachedFiles.FirstOrDefaultAsync(x => x.Id == Id).Select(x => new CachingStateVm(x.State)).ToProperty(this, x => x.CachingState);
}