MappingCollectionConstraint.php

<?php

declare (strict_types=1);
namespace Drupal\Core\Validation\Plugin\Validation\Constraint;

use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Validation\Attribute\Constraint;
use Drupal\Core\Validation\CompositeConstraintInterface;
use Symfony\Component\Validator\Constraints\Collection;

/**
 * Checks that at least one of the given constraints is satisfied.
 *
 * Overrides the Symfony constraint to convert the array of constraint IDs to an
 * array of constraint objects and use them.
 */
class MappingCollectionConstraint extends Collection implements CompositeConstraintInterface {
  
  /**
   * {@inheritdoc}
   */
  public static function getCompositeOptionStatic() : string {
    return 'fields';
  }

}