old_contents: import { createStore, applyMiddleware } from 'redux';
  import thunkMiddleWare from 'redux-thunk';
  import rootReducer from './../reducers';
  
  const createStoreWithMiddleware = applyMiddleware(
      thunkMiddleWare
  )(createStore);
  
  export default function configureStore() {
      return createStoreWithMiddleware(rootReducer);
  }
  
new_contents: import { createStore, applyMiddleware, compose } from 'redux';
  import thunkMiddleWare from 'redux-thunk';
  import rootReducer from './../reducers';
  
  const createStoreWithMiddleware = compose(
      applyMiddleware(thunkMiddleWare),
      window.devToolsExtension ? window.devToolsExtension() : f => f
  )(createStore);
  
  export default function configureStore() {
      return createStoreWithMiddleware(rootReducer);
  }
  
subject: add hook for Redux dev extension in Chrome