protected function process_book_chapter($data) {
        global $DB;

        $data = (object)$data;
        $oldid = $data->id;
        $data->course = $this->get_courseid();

        $data->bookid = $this->get_new_parentid('book');

        $newitemid = $DB->insert_record('book_chapters', $data);
        $this->set_mapping('book_chapter', $oldid, $newitemid, true);
    }