class StaticDiscoveryDecorator

ConstraintManager.php in drupal/core/lib/Drupal/Core/Validation/ConstraintManager.php

Contains \Drupal\Core\Validation\ConstraintManager.

class StaticDiscoveryDecorator extends StaticDiscovery {

  /**
   * The Discovery object being decorated.
   *
   * @var \Drupal\Component\Plugin\Discovery\DiscoveryInterface
   */
  protected $decorated;

  /**
   * A callback or closure used for registering additional definitions.
   *
   * @var \Callable
   */
  protected $registerDefinitions;

  /**
   * Constructs a \Drupal\Component\Plugin\Discovery\StaticDiscoveryDecorator object.
   *
   * @param \Drupal\Component\Plugin\Discovery\DiscoveryInterface $decorated
   *   The discovery object that is being decorated.
   * @param \Callable $registerDefinitions
   *   (optional) A callback or closure used for registering additional
   *   definitions.
   */
  public function __construct(DiscoveryInterface $decorated, $registerDefinitions = NULL) {
    $this->decorated = $decorated;
    $this->registerDefinitions = $registerDefinitions;
  }

  /**
   * Implements Drupal\Component\Plugin\Discovery\DiscoveryInterface::getDefinition().
   */
  public function getDefinition($base_plugin_id) {
    if (isset($this->registerDefinitions)) {
      call_user_func($this->registerDefinitions);
    }
    $this->definitions += $this->decorated
      ->getDefinitions();
    return parent::getDefinition($base_plugin_id);
  }

  /**
   * Implements Drupal\Component\Plugin\Discovery\DiscoveryInterface::getDefinitions().
   */
  public function getDefinitions() {
    if (isset($this->registerDefinitions)) {
      call_user_func($this->registerDefinitions);
    }
    $this->definitions += $this->decorated
      ->getDefinitions();
    return parent::getDefinitions();
  }

  /**
   * Passes through all unknown calls onto the decorated object
   */
  public function __call($method, $args) {
    return call_user_func_array(array(
      $this->decorated,
      $method,
    ), $args);
  }

}