Show exception detail in org.hippoecm.frontend.model.map.JcrMap

We want to get the exception detail from the following error logs:

ERROR [org.hippoecm.frontend.model.map.JcrMap.get():303] The session has
been closed. See the chained exception for a trace of where the session
was closed.

This error keeps happening occasionally, but it's hard to chase the cause because it doesn't give stack trace in detail.
So, we'd like to change the logging into something like 'log.error(ex.getMessage(), ex)'.