anchor.diff:  /** Enable/disable a test by ID. */
   void _setTestEnabledState(int testId, bool state) {
     // Try fast path first.
  -  if (_testCases.length > testId && _testCases[testId].id == testId) {
  -    _testCases[testId].enabled = state;
  +  if (testCases.length > testId && testCases[testId].id == testId) {
  +    testCases[testId].enabled = state;
     } else {
  -    for (var i = 0; i < _testCases.length; i++) {
  -      if (_testCases[i].id == testId) {
  -        _testCases[i].enabled = state;
  +    for (var i = 0; i < testCases.length; i++) {
  +      if (testCases[i].id == testId) {
  +        testCases[i].enabled = state;
           break;
         }
       }
  
positive.code:   int failed = 0;
    int errors = 0;
  
    for (TestCase t in _testCases) {
      switch (t.result) {
        case PASS:  passed++; break;
        case FAIL:  failed++; break;
  
negative.code: 
    ensureInitialized();
  
    _soloTest = new TestCase._internal(testCases.length + 1, _fullSpec(spec), body);
    testCases.add(_soloTest);
  }
  
  /** Sentinel value for [_SpreadArgsHelper]. */
  