Gatling 3.0.2 - Websocket ping pong


I saw that the ping pong between websocket both client and server was implemented in 3.0.2

I wonder if there’s any specific way to implement it because I don’t quite understand this in WebSocketHandler class :

else if (frame instanceof PingWebSocketFrame) {
ctx.write(new PongWebSocketFrame(frame.content().retain()));
} else if (frame instanceof PongWebSocketFrame) {
wsListener.onPongFrame((PongWebSocketFrame) frame);

How can we specify that the frame is an instance of PingWebSocketFrame and not of TextWebSocketFrame ?

And I woul’d like to know where are all logs generated by scala or java classes.

For example in WsListener.scala :

override def onPongFrame(frame: PongWebSocketFrame): Unit =
logger.debug(“Received PONG frame”)

I’ve been looking for a configuration file where this would be indicated but I can’t find anything…

Thank you in advance.