old_contents: import routerStateReducer from './routerStateReducer';
  import reduxRouteComponent from './reduxRouteComponent';
  import transitionTo from './transitionTo';
  
  export {
    routerStateReducer,
    reduxRouteComponent,
    transitionTo
  };
  
new_contents: import routerStateReducer from './routerStateReducer';
  import reduxRouteComponent from './reduxRouteComponent';
  import transitionTo from './transitionTo';
  import replaceWith from './replaceWith';
  
  export {
    routerStateReducer,
    reduxRouteComponent,
    transitionTo,
    replaceWith
  };
  
subject: add replaceWith to index