anchor.diff:  
   /** Get the list of tests. */
   List<TestCase> get testCases => _tests;
  -
  -/**
  - * Callback used to run tests. Entrypoints can replace this with their own
  - * if they want.
  - */
  -Function _testRunner;
   
   /** Setup function called before each test in a group */
   Function _testSetup;
  
positive.code:  * running. Tests will resume executing when such asynchronous test calls
   * [done] or if it fails with an exception.
   */
  _nextBatch() {
    while (true) {
      if (_currentTest >= _tests.length) {
        _completeTests();
  
negative.code: }
  
  /** Publish results on the page and notify controller. */
  void _completeTests() {
    if (!_initialized) return;
    int passed = 0;
    int failed = 0;
  