### Question:
BaseGameEngine extends BaseApp { @Override protected void addSubSystems(SubSystemManager manager) { manager.addSubSystem(new InputLayer(), false); manager.addSubSystem(new EventProcessor(Events.UI_THREAD, 10), false); manager.addSubSystem(new EventProcessor(Events.LOGIC_THREAD, 10), true); manager.addSubSystem(new NetworkView(), true); manager.addSubSystem(new GameLogicLayer(), true); manager.addSubSystem(new HumanView(), false); try { Class<?> cls = Class.forName("com.jukusoft.mmo.engine.cli.CommandLineInterface"); Runnable runnable = (Runnable) cls.newInstance(); Thread thread = new Thread(runnable); thread.setName("CLI"); thread.start(); Log.i("CLI", "command line interface started."); } catch (ClassNotFoundException e) { Log.i("CLI", "command line interface not integrated."); } catch (IllegalAccessException | InstantiationException e) { Log.w("CLI", "Coulnd't create CLI: ", e); } } BaseGameEngine(Version version);   }### Answer:
@Test public void testAddSubSystems () { BaseGameEngine engine = new BaseGameEngine(null); engine.addSubSystems(Mockito.mock(SubSystemManager.class)); }