code: private boolean registerListener(IServletContext webapp, String listenerClassName, ClassLoader classLoader) {
          try {
              ServletContextListener listener = (ServletContextListener) Class.forName(listenerClassName, true, classLoader).newInstance();
              webapp.addLifecycleListener(listener);
          } catch (Exception e) {
              if (log.isLoggable(Level.WARNING)) {
                  log.logp(Level.WARNING, CLASS_NAME, "registerListener", FacesMessages.getMsg("jsf.warn.exception.during.listener", new Object[] { listenerClassName,
                                                                                                                                                   applicationName }), e);
              }
              return false;
          }
          return true;
      }
docs: /*
  attempts to register a webapp lifecycle listener for the application. returns true if registration successful, false if not