anchor.diff:   * calls.
    */
   void test(String spec, TestFunction body) {
  -  _ensureActiveSuite();
  -
  -  _currentSuite._tests.add(new TestCase(
  -      _currentSuite._tests.length + 1, _fullSpec(spec), body, 0));
  +  _ensureInitialized();
  +
  +  _tests.add(new TestCase(_tests.length + 1, _fullSpec(spec), body, 0));
   }
   
   /**
  
positive.code: }
  
  /**
   * Lazily creates a UnitTestSuite if there isn't already an active one. Returns
   * whether or not one was created.
   */
  _ensureActiveSuite() {
    if (_currentSuite != null) {
      return;
    }
  
    _currentSuite = new UnitTestSuite();
  }
  
  /**
  
negative.code:  * body of the function passed to this will inherit this group's description.
   */
  void group(String description, void body()) {
    _ensureInitialized();
  
    // Concatenate the new group.
    final oldGroup = _currentGroup;
  