The old `ValidatorInterface` implementation is still used in two places: - [in the `Validation` class](https://github.com/symfony/symfony/blob/3.0/src/Symfony/Component/Validator/Validation.php#L27) - [in the `ValidatorBuilderInterface`](https://github.com/symfony/symfony/blob/3.0/src/Symfony/Component/Validator/ValidatorBuilderInterface.php#L166)