public static Bookmark CreateBookmark(this NativeActivityContext context, WaitForTaskAction action, BookmarkCallback callback)
        {
            using (StringWriter writer = new StringWriter())
            {
                SERIALIZER.Serialize(writer, action);

                return context.CreateBookmark(writer.ToString(), callback);
            }
        }
 /// <summary>
 /// Creates a point at which an activity can be resumed.
 /// </summary>
 /// <param name="context"></param>
 /// <param name="activity"></param>
 /// <returns></returns>
 public static Bookmark CreateTwilioBookmark(this NativeActivityContext context, Activity activity)
 {
     return context.CreateBookmark(CreateTwilioBookmarkName(context, activity));
 }
 /// <summary>
 /// Creates a point at which an activity can be resumed.
 /// </summary>
 /// <param name="context"></param>
 /// <param name="callback"></param>
 /// <returns></returns>
 public static Bookmark CreateTwilioBookmark(this NativeActivityContext context, BookmarkCallback callback)
 {
     return context.CreateBookmark(CreateTwilioBookmarkName(context, callback), callback);
 }