I would like to know if it is possible to get the class of the entity that is validated in the custom validator.

Here is the custom validator :

```
use Symfony\Component\Validator\Constraint;

class UniqueKey extends Constraint {
  public $message = 'The string "%string%" is not good';

  public function validatedBy() {
    return get_class($this).'Validator';
  }
}

class UniqueKeyValidator extends ConstraintValidator {
  public function validate($value, Constraint $constraint) {
    // I would like to get the class of the entity validated. Can I?
  }
}

```