public function asText(StringLength $length = null, array $allowedTags = [])
    {
        return $this->handleFilter(
                function() use($length, $allowedTags)
                {
                    $textFilter = new filter\TextFilter();
                    return filter\RangeFilter::wrap(
                            $textFilter->allowTags($allowedTags),
                            $length
                    );
                }
        );
    }