This is a little misleading. Right now, it's kind of true, but as of 2.5 this will be wrong.

The important fact is not whether or not I use group sequences. In 2.5, for example, the following will be possible:

```php
$validator->validate($object, new GroupSequence('Default', 'Strict'));
```

You see how this group sequence contains the "Default" group? And it's perfectly fine.

The reason why the group sequence can't contain the "Default" group here is that, by putting it on the class, we're *replacing* the "Default" group with the group sequence.