public function all()
    {
        if ($this->isEmpty()) {
            return [];
        }

        $arResult = [];
        foreach ($this->arElementIDList as $iElementID) {
            $obElementItem = $this->makeItem($iElementID, null);
            if ($obElementItem->isEmpty()) {
                continue;
            }

            $arResult[$iElementID] = $obElementItem;
        }

        return $arResult;
    }