public static void SetEncoded(this HtmlContentIntermediateNode node)
        {
            if (node == null)
            {
                throw new ArgumentNullException(nameof(node));
            }

            node.Annotations[HasEncodedContent] = HasEncodedContent;
        }
 public static bool IsEncoded(this HtmlContentIntermediateNode node)
 {
     return(ReferenceEquals(node.Annotations[HasEncodedContent], HasEncodedContent));
 }