How to find out current transaction timeout in Java EE 6?

Is there a way to find out the current transaction timeout (or even better the remainting time until timeout) of the current UserTransaction in Java EE 6?

I can inject UserTransaction in any CDI managed bean but the API has no such options.

If it isn't possible in plain Java EE, is there a way in JBoss 7.x/EAP 6.x?

Any ideas?

Thanks in advance.

Jan