PHP中ThinkPHP Collection对象如何转换为标准数组？

object(thinkcollection)#117 (1) {  ["items":protected] => array(10) {    [0] => array(5) {      ["id"] => int(2)      ["post_id"] => int(7)      ["category_id"] => int(9)      ["list_order"] => float(10000)      ["status"] => int(1)    }    ...  }}

$data->toarray();

array(10) {  [0] => array(5) {    ["id"] => int(2)    ["post_id"] => int(7)    ["category_id"] => int(9)    ["list_order"] => float(10000)    ["status"] => int(1)  }  ...}