private static function set_variables($title, $link, $description)
 {
     self::$icon = urlencode(Director::absoluteBaseURL() . 'favicon.ico');
     self::$non_encoded_page_url = Director::absoluteURL($link);
     self::$encoded_page_url = urlencode(self::$non_encoded_page_url);
     self::$encoded_page_title = urlencode($title);
     self::$encoded_page_title_space_encoded = str_replace('+', '%20', urlencode($title));
     if ($description) {
         self::$encoded_description = urlencode($description);
     } else {
         self::$encoded_description = self::$encoded_page_title;
     }
 }