Listen for PongWebSocketFrame in class annotated @ServerWebSocket

[bossman0072]

My websocket server is sending PingWebSocketFrame and then receives PongWebSocketFrame. How could I listen for that frame?
Source of AbstractNettyWebSocketHandler has code like this:
if (msg instanceof PongWebSocketFrame) { return; }
As I understand there is no way for handling PongWebSocketFrame. Am I right?

[graemerocher]

Looks like a limitation, what is the use case for listening for this frame?

[bossman0072]

Check if client is still connected. There is no way to change client code and add support for custom ping message.