protected function updateStats(&$target, $itemInfos)
    {
        if (!isset($target['stats'])) {
            $target['stats'] = [
                'questions' => 0,
                'answered' => 0,
                'flagged' => 0,
                'viewed' => 0,
                'total' => 0,
                'questionsViewed' => 0,
            ];
        }

        if (empty($itemInfos['informational'])) {
            $target['stats']['questions'] ++;

            if (!empty($itemInfos['answered'])) {
                $target['stats']['answered'] ++;
            }

            if (!empty($itemInfos['viewed'])) {
                $target['stats']['questionsViewed'] ++;
            }
        }

        if (!empty($itemInfos['flagged'])) {
            $target['stats']['flagged'] ++;
        }

        if (!empty($itemInfos['viewed'])) {
            $target['stats']['viewed'] ++;
        }

        $target['stats']['total'] ++;
    }