UniquePathAliasConstraint.php

<?php

namespace Drupal\Core\Path\Plugin\Validation\Constraint;

use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Validation\Attribute\Constraint;
use Symfony\Component\Validator\Attribute\HasNamedArguments;
use Symfony\Component\Validator\Constraint as SymfonyConstraint;

/**
 * Validation constraint for unique path alias values.
 */
class UniquePathAliasConstraint extends SymfonyConstraint {
  public function __construct(mixed $options = NULL, public $message = 'The alias %alias is already in use in this language.', public $differentCapitalizationMessage = 'The alias %alias could not be added because it is already in use in this language with different capitalization: %stored_alias.', ?array $groups = NULL, mixed $payload = NULL) {
    parent::__construct($options, $groups, $payload);
  }

}