anchor.diff:            fail('Should have thrown a RangeError');
           } catch (e) {
             expect(e, isRangeError);
  -          expect(e.message, expectedMessage == null
  -              ? 'index $index not valid for list of size $size'
  -              : expectedMessage);
  +          expect(
  +              e.message,
  +              expectedMessage == null
  +                  ? 'index $index not valid for list of size $size'
  +                  : expectedMessage);
           }
         }
         test('negative size', () => checkListIndexShouldFail(0, -1));
  
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('simple', () => checkArgument(true));
        test('null message', () => checkArgument(true, message: null));
        test('string message', () => checkArgument(true, message: 'foo'));
        test(
            'function message',
            () =>
                checkArgument(true, message: () => fail("Shouldn't be called")));
      });
  
      group('failure', () {
  