anchor.diff:      }
   
       elements.classes = [];
  -    for (Element e in elements) {
  -      expect(e.classes, []);
  -    }
  -    document.documentElement.children.remove(listElement);
  +    expect(view(elements.classes), '[]');
  +    expect(view(elements), '[[], [], [], []]');
     });
   
     test('listMap', () {
       var elements = listElementSetup();
       expect(elements.classes.map((c) => c.toUpperCase()).toList(),
           unorderedEquals(['QUX', 'QUUX', 'META', 'CLASSY', 'LASSY']));
  -    document.documentElement.children.remove(listElement);
     });
   
     test('listContains', () {
       var elements = listElementSetup();
       expect(elements.classes.contains('lassy'), isTrue);
       expect(elements.classes.contains('foo'), isFalse);
  -    document.documentElement.children.remove(listElement);
     });
   
   
  
positive.code:     expect(classes, orderedEquals(['foo', 'bar', 'aardvark', 'baz']));
    });
  
    Element listElement;
  
    ElementList<Element> listElementSetup() {
      listElement = makeListElement();
      document.documentElement.children.add(listElement);
      return document.queryAll('li');
    }
  
    test('listClasses=', () {
      var elements =  listElementSetup();
  
negative.code: 
    Element makeListElement() =>
      new Element.html('<ul class="foo bar baz">'
          '<li class="quux qux">'
          '<li class="meta">'
          '<li class="classy lassy">'
          '<li class="qux lassy">'
          '</ul>');
  
    Set<String> makeClassSet() => makeElementWithClasses().classes;
  
    Set<String> extractClasses(Element el) {
      final match = new RegExp('class="([^"]+)"').firstMatch(el.outerHtml);
      return new LinkedHashSet.from(match[1].split(' '));
    }
  
    /// Returns a canonical string for Set<String> and lists of Element's classes.
    String view(var e) {
      if (e is Set) return '${e.toList()..sort()}';
      if (e is Element) return view(e.classes);
      if (e is Iterable) return '${e.map(view).toList()}';
      throw new ArgumentError('Cannot make canonical view string for: $e}');
    }
  
    test('affects the "class" attribute', () {
  