Pagekit\Intl\IntlModule::getTerritoryContainment PHP Метод

    protected function getTerritoryContainment($level = 1, $locale = null)
    {
        static $tree;
        if (null === $tree) {
            $tree = [];
            $data = $this->getGeneric('territoryContainment');
            $build = function ($code, &$tree) use(&$build, $data) {
                $tree[$code] = [];
                if (isset($data[$code])) {
                    foreach ($data[$code] as $node) {
                        $build($node, $tree[$code]);
                    }
                }
            };
            $build('001', $tree);
        }
        $getLevel = function ($node, $depth = 1) use(&$getLevel, $level) {
            if ($level === $depth) {
                return $node;
            }
            $result = [];
            foreach ($node as $child) {
                $result += $getLevel($child, $depth + 1);
            }
            return $result;
        };
        return array_intersect_key($this->getTerritories($locale), $getLevel($tree['001']));
    }