看不懂这个语法了
<br /> /**<br /> * Get a Carbon instance for the current date and time<br /> *<br /> * @param DateTimeZone|string $tz<br /> *<br /> * @return static<br /> */<br /> public static function now($tz = null)<br /> {<br /> return new static(null, $tz);<br /> }<br />
