protected function getMaxPage()
    {
        $maxPageNumber = null;
        $maxPage       = null;
        foreach ($this->pages as $page) {
            $pageNumber = $page->getPageNumber();
            if ($maxPageNumber === null || $pageNumber > $maxPageNumber) {
                $maxPageNumber = $pageNumber;
                $maxPage       = $page;
            }
        }
        return $maxPage;
    }