outline-8.x-1.x-dev/modules/outline_graphql/src/Plugin/GraphQL/DataProducer/Outline/ServerUuid.php

<?php

namespace Drupal\outline_graphql\Plugin\GraphQL\DataProducer\Outline;

use Drupal\Core\Entity\EntityInterface;
use Drupal\graphql\Plugin\GraphQL\DataProducer\DataProducerPluginBase;
use Drupal\outline\Entity\Outline;

/**
 * @DataProducer(
 *   id = "server_uuid",
 *   name = @Translation("Server UUID"),
 *   description = @Translation("Returns the Sever UUID."),
 *   produces = @ContextDefinition("string",
 *     label = @Translation("Server UUID")
 *   )
 * )
 */
class ServerUuid extends DataProducerPluginBase {

  /**
   * @param \Drupal\outline\Entity\Outline $outline
   *
   * @return string
   */
  public function resolve() {
	  $server_uuid = \Drupal::config('system.site')->get('uuid');
          return $server_uuid;
  }

}