How to determine if html is invalid using Ganss.Xss.HtmlSanitizer?

Question

I am using Ganss.Xss.HtmlSanitizer to sanitize input html. By default the sanitizer silently remove invalid html. Instead, I would like to throw exception when input is invalid html.

using Ganss.Xss;
var sanitizer = new HtmlSanitizer();
var html = @"invalid html";
var sanitized = sanitizer.Sanitize(html, "https://www.example.com");

There are few event handlers but I am not sure what property to use that determines if the html is invalid

        var htmlSanitizer = new HtmlSanitizer();
        htmlSanitizer.PostProcessNode += (s, e) =>
        {
            //What determines here that node is invalid?
        };