/**
  * Returns a list of the install storage items for an extension.
  *
  * @param string $type
  *   Type of extension ('module', etc.).
  * @param string $name
  *   Machine name of extension.
  * @param bool $do_optional
  *   FALSE (default) to list config/install items, TRUE to list
  *   config/optional items.
  *
  * @return string[]
  *   List of config items provided by this extension.
  */
 protected function listProvidedItems($type, $name, $do_optional = FALSE)
 {
     $pathname = drupal_get_filename($type, $name);
     $component = new Extension(\Drupal::root(), $type, $pathname);
     if ($do_optional) {
         $names = $this->extensionOptionalConfigStorage->getComponentNames(array($component));
     } else {
         $names = $this->extensionConfigStorage->getComponentNames(array($component));
     }
     return array_keys($names);
 }