anchor.diff:  
   void getPackage(Event event) {
     String name = (querySelector("#package") as InputElement).value;
  -  String url = '$dartdocs/$name/latest/';
  -  HttpRequest.getString(url).then((data) => redirectToPackageVersion(data, name));
  +  if (name.startsWith('dart:')) {
  +    name = name.replaceFirst(':', '-');
  +    // https://api.dartlang.org/apidocs/channels/stable/docs/dart-collection.json
  +    // https://api.dartlang.org/apidocs/channels/stable/docs/dart-collection.DoubleLinkedQueue.json
  +    base = '$apidocs';
  +    gapsDiv.innerHtml = '';
  +    new LibraryDocAnalyzer(name)..go();
  +  }
  +  else {
  +    // http://www.dartdocs.org/documentation/args/0.12.1/index.html
  +    // http://www.dartdocs.org/documentation/args/0.12.1/docs/library_list.json
  +    // http://www.dartdocs.org/documentation/args/0.12.1/docs/args/args.json
  +    // http://www.dartdocs.org/documentation/args/0.12.1/docs/args/args.ArgParser.json
  +    String url = '$dartdocs/$name/latest/';
  +    HttpRequest.getString(url).then((data) => redirectToPackageVersion(data, name));
  +  }
   }
   
   void redirectToPackageVersion(String html, String name) {
  
positive.code:   else reportClassGaps(gaps);*/
  }
  
  void reportPackages(String json) {
    Map<String,dynamic> package;
    dynamic _package = new JsonDecoder().convert(json);
    if (_package is Map) {
  
negative.code:     versionUrl = '$dartdocs/$name/$version/index.html';
      base = '$dartdocs/$name/$version/docs';
      String url = '$base/library_list.json';
      HttpRequest.getString(url).then(reportPackage);
    } else {
      gapsDiv.text = 'Error! $html';
    }
  }
  
  