This property getter must be called with the PerformanceResourceTiming object as the receiver.
PerformanceResourceTiming
新增于: v18.2.0, v16.17.0
高精度毫秒时间戳，表示 Node.js 完成与服务器建立连接以获取资源后立即的时间。
【The high resolution millisecond timestamp representing the time immediately after Node.js finishes establishing the connection to the server to retrieve the resource.】