anchor.diff:  /**
    * Allocate a Configuration. We allocate either a parent or child, depending on
    * whether the URL has a search part.
  - * 
  + *
    * Note: this unit test configuration will not work with the debugger (the tests
    * are executed in a separate IFrame).
    */
  
positive.code:     window.onMessage.listen((MessageEvent e) {
        // Get the result, do any logging, then do a pass/fail.
        var m = new _Message.fromString(e.data);
        if (m.messageType == _Message.START) {
          parentWindow = e.source;
          String search = window.location.search;
          int pos = search.indexOf('t=');
          String ids = search.substring(pos+2);
  
negative.code: import 'unittest.dart';
  
  /** The messages exchanged between parent and child. */
  class _Message {
    static const START = 'start';
    static const LOG = 'log';
  