class ClosureLoader

1. 9.x drupal/core/vendor/symfony/routing/Symfony/Component/Routing/Loader/ClosureLoader.php \Symfony\Component\Routing\Loader\ClosureLoader
2. 9.x drupal/core/vendor/symfony/dependency-injection/Symfony/Component/DependencyInjection/Loader/ClosureLoader.php \Symfony\Component\DependencyInjection\Loader\ClosureLoader

ClosureLoaderTest.php in drupal/core/vendor/symfony/dependency-injection/Symfony/Component/DependencyInjection/Tests/Loader/ClosureLoaderTest.php

Kernel.php in drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Kernel.php

class ClosureLoader extends Loader {
  private $container;

  /**
   * Constructor.
   *
   * @param ContainerBuilder $container A ContainerBuilder instance
   */
  public function __construct(ContainerBuilder $container) {
    $this->container = $container;
  }

  /**
   * Loads a Closure.
   *
   * @param \Closure $closure The resource
   * @param string   $type    The resource type
   */
  public function load($closure, $type = null) {
    call_user_func($closure, $this->container);
  }

  /**
   * Returns true if this class supports the given resource.
   *
   * @param mixed  $resource A resource
   * @param string $type     The resource type
   *
   * @return Boolean true if this class supports the given resource, false otherwise
   */
  public function supports($resource, $type = null) {
    return $resource instanceof \Closure;
  }

}