modify_domain接口中为什么同样的域名要传两个

{

"action":"add",

"requestdomain":["https://www.qq.com","https://www.qq.com"],

"wsrequestdomain":["wss://www.qq.com","wss://www.qq.com"],

"uploaddomain":["https://www.qq.com","https://www.qq.com"],

"downloaddomain":["https://www.qq.com","https://www.qq.com"],

           }

如上所示，为什么每个domain中要传两个同样的域名。多谢