reactjs – React redux：无法设置不可变记录

import { List,Record } from 'immutable';
import { IFaqItem } from './api.models';

export interface IFaqsState {
  loading?: boolean;
  items?: List<IFaqItem>;
}
const faqsState = Record({
  loading: false,items: List()
});

class FaqsState extends faqsState implements IFaqsState {
  loading: boolean;
  items: List<IFaqItem>;

  with(props: IFaqsState) {
    this.set('loading',props.loading);
    return this;
  }
}

export default FaqsState;

reducer包含以下内容：

case ActionTypes.FAQS_GET_AJAX_RECEIVE:
  let response: IFaqsGetResponse = action.payload.response && action.payload.response.response;
  return state.with({
    loading: false,items: List(response)
  });

但是,这给了我以下错误：

Error: Cannot set on an immutable record.

UPDATE

当我更改减速器时：

let initial = new FaqsState();

const faqsReducer: Reducer<FaqsState> = (state = initial,action: AppActions) => {

至：

const faqsReducer: Reducer<FaqsState> = (state = null,action: AppActions) => {

  state = new FaqsState();

它似乎工作.当我将初始状态作为参数时,为什么它不起作用？