code: private void closeRemainingBrowsers()
      {
          List<AbstractQueueBrowser> browsersToClose = new ArrayList<>(browsersMap.size());
          synchronized (browsersMap)
          {
          	browsersToClose.addAll(browsersMap.values());
          }
          for (int n = 0 ; n < browsersToClose.size() ; n++)
          {
          	QueueBrowser browser = browsersToClose.get(n);
              log.debug("Auto-closing unclosed browser : "+browser);
              try
              {
                  browser.close();
              }
              catch (Exception e)
              {
                  log.error("Could not close browser "+browser,e);
              }
          }
      }
docs: Close remaining browsers