### Question:
ApplicationCore { public void detach() { if (attached) { runtimeAgg.stop(); attached = false; if (CREATE_MOCK_RAINBOW) { mockRainbow.cancel(); } } } protected  ApplicationCore(); static ApplicationCore getInstance(); void startup(String filename); void attach(); void detach(); String getWriteSession(); ArrayList<String> getSessionList(); boolean isAttached(); static void registerWidgets(); IRuntimeAggregator<?> getRuntimeAggregator(); ISystemConfiguration getSystemConfiguration(); ArrayList<String> getViewConfigurations(); ViewConfiguration getViewConfiguration(String name); String getLatestViewConfigurationName(); void saveViewConfiguration(ViewConfiguration config, String name);  }### Answer:
@Test public void testDetach() { instance.detach(); assertEquals(instance.isAttached(), false); }