How to use the react-onsenui.RouterUtil.pop function in react-onsenui

popPage(options = {}) {
    let routeConfig = this.state.routeConfig;

    routeConfig = RouterUtil.pop({
      routeConfig,
      options: {
        ...options,
        animationOptions: {duration: 0.4}
      }
    });

    this.setState({routeConfig});
  }

const reducer = (state = initialState, action) => {
  let routeConfig;

	switch(action.type) {
		case 'PUSH_PAGE':
      const {route} = action;
      routeConfig = state;
      return RouterUtil.push({routeConfig, route});
		case 'POST_PUSH':
      return RouterUtil.postPush(state);
		case 'POP_PAGE':
      routeConfig = state;
      return RouterUtil.pop({routeConfig});
		case 'POST_POP':
      return RouterUtil.postPop(state);
		default:
			return state;
	}
};