### Question:
CommandHelper { public static List<Class<?>> getAllCommandClass(){ final Set<String> commandList = ExtensionLoader.getExtensionLoader(BaseCommand.class).getSupportedExtensions(); final List<Class<?>> classes = new ArrayList<Class<?>>(); for (String commandName : commandList) { BaseCommand command = ExtensionLoader.getExtensionLoader(BaseCommand.class).getExtension(commandName); classes.add(command.getClass()); } return classes; }  static boolean hasCommand(String commandName); static List<Class<?>> getAllCommandClass(); static Class<?> getCommandClass(String commandName);  }### Answer:
@Test public void testGetAllCommandClass() throws Exception { List<Class<?>> classes = CommandHelper.getAllCommandClass(); assertThat(classes, containsInAnyOrder(GreetingCommand.class, Help.class, Ls.class, Offline.class, Online.class, Quit.class)); }