C# HtmlAgilityPack inner html dont change after appending node

In my C# i change loaded html, and need to get html document as plain text. But whenever i append new node to one of document's node, the inner html of root node doesn't change, even if the new node is successfully added. After debugging i noticed that only the parents of new node has the change in their InnerHtml property, for example: ``` HtmlDocument doc; HtmlNode root doc.DocumentNode; HtmlNode node2 = root.ChildNodes[1]; HtmlNode newNode = new HtmlNode(...); node2.Append(newNode); ``` Having: ``` <root> <node1> </node1> <node2> <node3> <node3> <newNode> </newNode> </node2> </root> ``` node2.InnerHtml will be ``` <node3> <node3> <newNode> </newNode> ``` but root.InnerHtml is ``` <root> <node1> </node1> <node2> <node3> <node3> </node2> </root> ``` How can i fix this right? ( i know i could manually update every document's node inner html, but common... )