text: /** 
   * 
  */
  import { createStore } from 'redux';
  import todoApp from './reducers';
  import { addTodo, toggleTodo, setVisibilityFilter, VisibilityFilters } from './actions';
  
  let store = createStore(todoApp);
  
  // 打印初始状态
  console.log(store.getState());
  
  // 每次 state 更新时，打印日志
  // 注意 subscribe() 返回一个函数用来注销监听器
  let unsubscribe = store.subscribe(() =>
      console.log(store.getState())
  );
  
  // 发起一系列 action
  store.dispatch(addTodo('Learn about actions'));
  store.dispatch(addTodo('Learn about reducers'));
  store.dispatch(addTodo('Learn about store'));
  store.dispatch(toggleTodo(0));
  store.dispatch(toggleTodo(1));
  store.dispatch(setVisibilityFilter(VisibilityFilters.SHOW_COMPLETED));
  
  // 停止监听 state 更新
  unsubscribe();
  
  
  