code: @Override
      public void destroy() {
          if (timerFilterThread != null) {
              timerFilterThread.setStopped();
              timerFilterThread = null;
          }
  
          Filter filter = null;
          for (int i=0; i<filterFactory.getAllFilter().size(); i++) {
              // ZAP: Removed unnecessary cast.
              filter = filterFactory.getAllFilter().get(i);
              try {
                  filter.destroy();
              } catch (Exception e) {}
          }
          
          
      }
docs: Destroy every filter during extension destroy.