old_contents: import { isApp } from './utils/feature';
  import store from './store';
  import rootSaga from './sagas';
  import 'babel-polyfill';
  
  store.runSaga(rootSaga);
  
new_contents: import store from './store';
  import rootSaga from './sagas';
  import 'babel-polyfill';
  
  store.runSaga(rootSaga);
  
subject: remove unused