### Question:
ApplicationCore { public void startup(String filename) throws Exception { sysConfig = new SystemConfiguration(filename); try { startBackground(); } catch (Exception e) { throw e; } registerWidgets(); } 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 testStartup() throws Exception { assertEquals(instance.isAttached(), true); }