public function getList(Category $Parent = null, $flat = false)
    {
        $options = $this->app['config']['doctrine_cache'];
        $lifetime = $options['result_cache']['lifetime'];

        $qb = $this->createQueryBuilder('c1')
            ->select('c1, c2, c3, c4, c5')
            ->leftJoin('c1.Children', 'c2')
            ->leftJoin('c2.Children', 'c3')
            ->leftJoin('c3.Children', 'c4')
            ->leftJoin('c4.Children', 'c5')
            ->orderBy('c1.rank', 'DESC')
            ->addOrderBy('c2.rank', 'DESC')
            ->addOrderBy('c3.rank', 'DESC')
            ->addOrderBy('c4.rank', 'DESC')
            ->addOrderBy('c5.rank', 'DESC');

        if ($Parent) {
            $qb->where('c1.Parent = :Parent')->setParameter('Parent', $Parent);
        } else {
            $qb->where('c1.Parent IS NULL');
        }
        $Categories = $qb->getQuery()
            ->useResultCache(true, $lifetime)
            ->getResult();

        if ($flat) {
            $array = array();
            foreach ($Categories as $Category) {
                $array = array_merge($array, $Category->getSelfAndDescendants());    // ★ ここを改善したい
            }
            $Categories = $array;
        }

        return $Categories;
    }

        $Categories = array();
        $AllCategories = $this->app['eccube.repository.category']
            // ->getList(null, true);
            ->getList();
        foreach ($AllCategories as $Category) {
            $Parent = $Category->getParent();
            if (!$Parent) {
                $Categories[] = $Category;
                continue;
            }
            $Parent = $Parent->getParent();
            if (!$Parent) {
                $Categories[] = $Category;
                continue;
            }
        }

        $Categories = $this->app['eccube.repository.category']
            // ->getList(null, true);
            ->findBy(array());