class HelpSectionManager

class HelpSectionManager extends DefaultPluginManager {
    
    /**
     * The search manager.
     *
     * @var \Drupal\Component\Plugin\PluginManagerInterface
     */
    protected ?PluginManagerInterface $searchManager = NULL;
    
    /**
     * Constructs a new HelpSectionManager.
     *
     * @param \Traversable $namespaces
     *   An object that implements \Traversable which contains the root paths
     *   keyed by the corresponding namespace to look for plugin implementations.
     * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
     *   Cache backend instance to use.
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     *   The module handler for the alter hook.
     */
    public function __construct(\Traversable $namespaces, CacheBackendInterface $cache_backend, ModuleHandlerInterface $module_handler) {
        parent::__construct('Plugin/HelpSection', $namespaces, $module_handler, 'Drupal\\help\\HelpSectionPluginInterface', HelpSection::class, 'Drupal\\help\\Annotation\\HelpSection');
        $this->alterInfo('help_section_info');
        $this->setCacheBackend($cache_backend, 'help_section_plugins');
    }
    
    /**
     * Sets the search manager.
     *
     * @param \Drupal\Component\Plugin\PluginManagerInterface|null $search_manager
     *   The search manager if the Search module is installed.
     */
    public function setSearchManager(?PluginManagerInterface $search_manager = NULL) {
        $this->searchManager = $search_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public function clearCachedDefinitions() {
        parent::clearCachedDefinitions();
        // Search module may be missing. Help module might be installing,
        // so its search plugin may not be discovered yet.
        if ($this->searchManager && $this->searchManager
            ->hasDefinition('help_search')) {
            // Rebuild the index on cache clear so that new help topics are indexed
            // and any changes due to help topics edits or translation changes are
            // picked up.
            $help_search = $this->searchManager
                ->createInstance('help_search');
            $help_search->markForReindex();
        }
    }

}