/** * @return array */ public static function abWinnerCriteria() { if (!is_array(self::$abWinnerCriteria)) { self::$abWinnerCriteria = array('open' => ts('Open'), 'unique_click' => ts('Total Unique Clicks'), 'link_click' => ts('Total Clicks on a particular link')); } return self::$abWinnerCriteria; }