@Override
 public void goalRaisedException(AsyncPrologSessionEvent e) {
   Debug.error(
       "Goal raised exception: " + e.message + "\n query: " + e.query + "\n ticket: " + e.ticket);
 }
 @Override
 public void batchError(AsyncPrologSessionEvent e) {
   Debug.error(
       "Fatal error during batch processing (probably the connection to the server was lost).");
 }
 @Override
 public void goalFailed(AsyncPrologSessionEvent e) {
   Debug.info("Goal failed: " + e.query);
 }