通过消息关闭Websocket连接

How is it possible to close a websocket connection and pass it a message / code?

The docs only define func (ws *Conn) Close() error without any arguments

I would like to receive the event from JavaScript like this:

websocket.onclose = function(event) {
  console.log(event);
};

I am using golang.org/x/net/websocket

Send a close message before closing the connection:

 cm := websocket.FormatCloseMessage(websocket.CloseNormalClosure, "add your message here")
 if err := c.WriteMessage(websocket.CloseMessage, cm); err != nil {
     // handle error
 }
 c.Close()

It is not possible to specify the close message with the golang.org/x/net/websocket package.