code: public static JMXControl getFromEvent(ApplicationEvent event) {
      	if (event instanceof ApplicationContextEvent) {
      		return getFromContext(((ApplicationContextEvent) event).getApplicationContext());
      	}
      	else {
      		return null;
      	}
      }
docs: Return JMXControl bean from the ApplicationContext *if* the given event is
  an {@link ApplicationContextEvent} (or null otherwise).
  <p>
  A utility method wrapping one way in which we'd call
  {@link #getFromContext(ApplicationContext)}.