anchor.diff:  import 'dart:async';
   import 'dart:html';
   import 'dart:mirrors' hide Comment;
  +import 'dart:svg';
   
   import 'src/core.dart';
   import 'src/interfaces.dart';
  
positive.code: 
    @override
    Future click({bool sync: true}) => loader.executeSynced(() {
          if (node is OptionElement) {
            return _clickOptionElement();
          } else {
            return _microtask(node.click);
          }
        }, sync);
  
    Future _clickOptionElement() {
      OptionElement option = node as OptionElement;
  
negative.code:   @override
    _HtmlMouse get mouse => _mouse;
  
    HtmlPageLoader(Node globalContext, {bool useShadowDom: true,
        SyncedExecutionFn executeSyncedFn: noOpExecuteSyncedFn})
        : super(useShadowDom: useShadowDom, executeSyncedFn: executeSyncedFn) {
      this._globalContext = new HtmlPageLoaderElement(globalContext, this);
  