how to integrate redux dev tool to react application

1 const store = createStore(
2   reducer, /* preloadedState, */
3+  window.__REDUX_DEVTOOLS_EXTENSION__ && window.__REDUX_DEVTOOLS_EXTENSION__()
4 );

1  import { createStore, applyMiddleware, compose } from 'redux';
2
3 const composeEnhancers = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ || compose;
4 const store = createStore(reducer, /* preloadedState, */ composeEnhancers(
5    applyMiddleware(...middleware)
6  ));