How do I trap the Exit Cancel response??

We have added a new controller that gets fired when the user uses thw WIH Exit button.
However if you change your mind in response to "Would you like to exit Work Item Handler " the respone (out-of-the-box at least) is not captured to force the .setStop to be called.
At the moment WM fires off the controller regardless.

How do I trap the WIH message response?

Thanks