public static async Task<Stream> BigThumbnailAsync(this TimeLapsedImage image)
 {
     return await image.BigThumbnailAsync(image.Name);
 }
 public static async Task<Stream> BigThumbnailAsync(this TimeLapsedImage image,int index)
 {
     var name = image.IndexName(index);
     return await image.BigThumbnailAsync(name);
 }