事件：'close'

【Event: 'close'】

• hadError <boolean> 如果套接字发生传输错误，则为 true。

当套接字完全关闭时触发。参数 hadError 是一个布尔值，用于表示套接字是否由于传输错误而关闭。

【Emitted once the socket is fully closed. The argument hadError is a boolean which says if the socket was closed due to a transmission error.】