anchor.diff:   */
   void test(String spec, TestFunction body) {
     ensureInitialized();
  -  _testCases.add(new TestCase._internal(_testCases.length + 1, _fullSpec(spec),
  -                                        body));
  +  testCases.add(new TestCase._internal(testCases.length + 1, _fullSpec(spec),
  +                                       body));
   }
   
   /**
  
positive.code: void _registerException(testNum, e, [trace]) {
    trace = trace == null ? '' : trace.toString();
    String message = (e is TestFailure) ? e.message : 'Caught $e';
    if (_testCases[testNum].result == null) {
      _testCases[testNum].fail(message, trace);
    } else {
      _testCases[testNum].error(message, trace);
    }
  }
  
  
negative.code:  *  error was caught outside of this library.
   */
  void _reportTestError(String msg, String trace) {
   if (_currentTestCaseIndex < testCases.length) {
      final testCase = testCases[_currentTestCaseIndex];
      testCase.error(msg, trace);
    } else {
      _uncaughtErrorMessage = "$msg: $trace";
  