convertCategories example

'shopContext' => $context,
            'config' => $this->Config(),
        ]);

        $cache = $this->get(Zend_Cache_Core::class);

        if ($this->Config()->get('caching') && $cache->test($cacheKey)) {
            $menu = $cache->load($cacheKey, true);
        } else {
            $ids = $this->getCategoryIdsOfDepth($category, (int) $depth);
            $categories = $this->get(CategoryServiceInterface::class)->getList($ids, $context);
            $categoriesArray = $this->convertCategories($categories);
            $categoryTree = $this->getCategoriesOfParent($category, $categoriesArray);
            if ($this->Config()->get('caching')) {
                $cache->save($categoryTree, $cacheKey, ['Shopware_Plugin'], (int) $this->Config()->get('cachetime', 86400));
            }
            $menu = $categoryTree;
        }

        $categoryPath = $this->getCategoryPath($activeCategoryId);

        return $this->setActiveFlags($menu, $categoryPath);
    }