### Question:
MvcNavigationSystemEventListener implements SystemEventListener { public boolean isListenerForSource(Object source) { return true; }  boolean isListenerForSource(Object source); void processEvent(SystemEvent event); static PreRenderComponentEvent getLastPreRenderComponentEvent(FacesContext context);  }### Answer:
@Test public void shouldListenForAllSources() throws Exception { Object source = new Object(); assertThat(this.listener.isListenerForSource(source), is(true)); }