DirectoryWithMetadataPluginDiscovery example

    return $library;
  }

  /** * {@inheritdoc} */
  protected function getDiscovery(): DirectoryWithMetadataPluginDiscovery {
    if (!isset($this->discovery)) {
      $directories = $this->getScanDirectories();
      $this->discovery = new DirectoryWithMetadataPluginDiscovery($directories, 'sdc', $this->fileSystem);
    }
    return $this->discovery;
  }

  /** * {@inheritdoc} */
  protected function providerExists($provider) {
    return $this->moduleHandler->moduleExists($provider) || $this->themeHandler->themeExists($provider);
  }