class SectionStorageManager

class SectionStorageManager extends DefaultPluginManager implements SectionStorageManagerInterface {
    
    /**
     * The context handler.
     *
     * @var \Drupal\Core\Plugin\Context\ContextHandlerInterface
     */
    protected $contextHandler;
    
    /**
     * Constructs a new SectionStorageManager object.
     *
     * @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 to invoke the alter hook with.
     * @param \Drupal\Core\Plugin\Context\ContextHandlerInterface $context_handler
     *   The context handler.
     */
    public function __construct(\Traversable $namespaces, CacheBackendInterface $cache_backend, ModuleHandlerInterface $module_handler, ContextHandlerInterface $context_handler) {
        parent::__construct('Plugin/SectionStorage', $namespaces, $module_handler, SectionStorageInterface::class, SectionStorage::class);
        $this->contextHandler = $context_handler;
        $this->alterInfo('layout_builder_section_storage');
        $this->setCacheBackend($cache_backend, 'layout_builder_section_storage_plugins');
    }
    
    /**
     * {@inheritdoc}
     */
    protected function findDefinitions() {
        $definitions = parent::findDefinitions();
        // Sort the definitions by their weight while preserving the original order
        // for those with matching weights.
        $weights = array_map(function (SectionStorageDefinition $definition) {
            return $definition->getWeight();
        }, $definitions);
        $ids = array_keys($definitions);
        array_multisort($weights, $ids, $definitions);
        return $definitions;
    }
    
    /**
     * {@inheritdoc}
     */
    public function load($type, array $contexts = []) {
        $plugin = $this->loadEmpty($type);
        try {
            $this->contextHandler
                ->applyContextMapping($plugin, $contexts);
        } catch (ContextException $e) {
            return NULL;
        }
        return $plugin;
    }
    
    /**
     * {@inheritdoc}
     */
    public function findByContext(array $contexts, RefinableCacheableDependencyInterface $cacheability) {
        $storage_types = array_keys($this->contextHandler
            ->filterPluginDefinitionsByContexts($contexts, $this->getDefinitions()));
        // Add the manager as a cacheable dependency in order to vary by changes to
        // the plugin definitions.
        $cacheability->addCacheableDependency($this);
        foreach ($storage_types as $type) {
            $plugin = $this->load($type, $contexts);
            if ($plugin && $plugin->isApplicable($cacheability)) {
                return $plugin;
            }
        }
        return NULL;
    }
    
    /**
     * {@inheritdoc}
     */
    public function loadEmpty($type) {
        return $this->createInstance($type);
    }

}