anchor.diff:  
         test('no message', () => checkStateShouldFail(() => checkState(false)));
   
  -      test('failure and simple string message', () => checkStateShouldFail(
  -          () => checkState(false, message: 'message'), 'message'));
  +      test(
  +          'failure and simple string message',
  +          () => checkStateShouldFail(
  +              () => checkState(false, message: 'message'), 'message'));
   
         test('failure and null message',
             () => checkStateShouldFail(() => checkState(false, message: null)));
  -      test('message closure returns null', () =>
  -          checkStateShouldFail(() => checkState(false, message: () => null)));
  +      test(
  +          'message closure returns null',
  +          () => checkStateShouldFail(
  +              () => checkState(false, message: () => null)));
   
         test('failure and message function', () {
           int five = 5;
  
positive.code:       test('no message',
            () => checkArgumentShouldFail(() => checkArgument(false)));
  
        test('failure and simple string message', () => checkArgumentShouldFail(
            () => checkArgument(false, message: 'message'), 'message'));
  
        test('failure and null message', () =>
            checkArgumentShouldFail(() => checkArgument(false, message: null)));
        test('failure and object as message', () =>
            checkArgumentShouldFail(() => checkArgument(false, message: 5), '5'));
        test('failure and message closure returns object',
            () => checkArgumentShouldFail(
                () => checkArgument(false, message: () => 5), '5'));
  
  
negative.code:       test(
            'no message', () => checkNotNullShouldFail(() => checkNotNull(null)));
  
        test(
            'simple failure message',
            () => checkNotNullShouldFail(
                () => checkNotNull(null, message: 'message'), 'message'));
  
        test(
            'null message',
            () =>
                checkNotNullShouldFail(() => checkNotNull(null, message: null)));
  
        test(
            'message closure returns null',
            () => checkNotNullShouldFail(
                () => checkNotNull(null, message: () => null)));
  
        test('failure and message function', () {
          int five = 5;
  