public static string GetTrackUrl(this ISpotifyActivity activity) => $"https://open.spotify.com/track/{activity.TrackId}";
public static TimeSpan GetRemainingDuration(this ISpotifyActivity activity) => activity.EndsAt - DateTimeOffset.UtcNow;
public static TimeSpan GetDuration(this ISpotifyActivity activity) => activity.EndsAt - activity.StartedAt;
public static TimeSpan GetElapsedDuration(this ISpotifyActivity activity) => DateTimeOffset.UtcNow - activity.StartedAt;
public static string GetAlbumCoverUrl(this ISpotifyActivity activity) => activity.AlbumId != null ? $"https://i.scdn.co/image/{activity.AlbumId}" : null;