DuplicateConfigAction.php

<?php

namespace Drupal\config_action_duplicate_test\Plugin\ConfigAction;

use Drupal\Core\Config\Action\Attribute\ConfigAction;
use Drupal\Core\Config\Action\ConfigActionPluginInterface;
use Drupal\Core\StringTranslation\TranslatableMarkup;
final class DuplicateConfigAction implements ConfigActionPluginInterface {
  
  /**
   * {@inheritdoc}
   */
  public function apply(string $configName, mixed $value) : void {
    // This method should never be called.
    throw new \BadMethodCallException();
  }

}