When creating Symfony Validator constraints, like this: ```php final class Phone extends Constraint { public const string PHONE_NUMBER_INVALID = 'b4093308-a26b-41cb-8248-5ec6583c77bf'; public string $message = 'The phone number "%phone%" is not valid'; public bool $allowEmpty = false; /** * @var array<string, string> */ protected const array ERROR_NAMES = [ self::PHONE_NUMBER_INVALID => 'PHONE_NUMBER_INVALID', ]; #[Override] public function validatedBy() : string { return PhoneValidator::class; } } ``` It complains that the `ERORR_NAMES` constant is not used. But it's part of the parent Constraint contract. ```php abstract class Constraint { /** * Maps error codes to the names of their constants. * * @var array<string, string> */ protected const ERROR_NAMES = []; } ```