text: // 页面需要什么状态? 用户信息显示， token 
  import * as types from '../action-types'
  
  const initState = {
      sidebarCollapsed: false, 
      settingPanelVisible: false
  }
  export default function app(state = initState, action) {
      switch(action.type) {
          case types.SET_APP_SIDEBAR_COLLAPSED:
              return {
                  ...state,
                  sidebarCollapsed: !state.sidebarCollapsed
              }
          default:
              return state
      }
  }