code: public void cleanup() {
          List<Threshold> th = getThresholds();
          for (Threshold t : th) {
              final String tName = t.getDefinition().getName();
              try {
              	MBeanUtil.getInstance().unregisterMBean(createName(tName));
              } catch (MBeanRegistrationException e) {
  				log.warn("can't unregister " + tName + ", ignored.", e);
  			}
  		}
          super.cleanup();
      }
docs: removes all {@link Threshold} MBeans from platform MBeanServer.