class PhpFileLoader

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

PhpFileLoaderTest.php in drupal/core/vendor/symfony/routing/Symfony/Component/Routing/Tests/Loader/PhpFileLoaderTest.php

class PhpFileLoader extends FileLoader {

  /**
   * Loads a PHP file.
   *
   * @param string      $file A PHP file path
   * @param string|null $type The resource type
   *
   * @return RouteCollection A RouteCollection instance
   *
   * @api
   */
  public function load($file, $type = null) {

    // the loader variable is exposed to the included file below
    $loader = $this;
    $path = $this->locator
      ->locate($file);
    $this
      ->setCurrentDir(dirname($path));
    $collection = (include $path);
    $collection
      ->addResource(new FileResource($path));
    return $collection;
  }

  /**
   * {@inheritdoc}
   *
   * @api
   */
  public function supports($resource, $type = null) {
    return is_string($resource) && 'php' === pathinfo($resource, PATHINFO_EXTENSION) && (!$type || 'php' === $type);
  }

}