protected function csv($key = null, $default = null)
    {
        if (empty($this->contentAsArray)) {
            $content = $this->getContent();
            $data = DataFormatter::csvToArray($content);

            if (!empty($data)) {
                $this->contentAsArray = ResourcesWrapper::wrapResources($data);
            }
        }

        if (null === $key) {
            return $this->contentAsArray;
        } else {
            return array_get($this->contentAsArray, $key, $default);
        }
    }