anchor.diff:    }
   }
   
  +class TrustedHtmlTreeSanitizer implements NodeTreeSanitizer {
  +  const TrustedHtmlTreeSanitizer();
  +
  +  void sanitizeTree(Node node) { }
  +}
  +
   Future<Map> loadPackageJson() {
     return HttpRequest.getString('atom://dartlang/package.json').then((str) {
       return JSON.decode(str);
  
positive.code:     <div class="message">${prompt}</div>
  ''',
        validator: new PermissiveNodeValidator(),
        treeSanitizer: NodeTreeSanitizer.trusted);
  
    Element editorElement = element.querySelector('atom-text-editor');
    JsFunction editorConverter = context['getTextEditorForElement'];
  
negative.code: 
  import 'dart:async';
  import 'dart:convert' show JSON;
  import 'dart:html' show DivElement, Element, HttpRequest, Node, NodeValidator,
      NodeTreeSanitizer, window;
  import 'dart:js';
  
  