如何使用类函数初始化redux状态？

import { createStore } from 'redux';
import { Provider } from 'react-redux';

const initialState = {
  counter: 0,
  todos: []
};

const reducer = (state = initialState, action) => {
  switch (action.type) {
    case 'INCREMENT':
      return {
        ...state,
        counter: state.counter + 1
      };
    case 'ADD_TODO':
      return {
        ...state,
        todos: [...state.todos, action.payload]
      };
    default:
      return state;
  }
};

const store = createStore(reducer);

const App = () => {
  return (
    <Provider store={store}>
      {/* 应用的其他组件 */}
    </Provider>
  );
};

import { connect } from 'react-redux';

const Counter = ({ counter, increment }) => {
  return (
    <div>
      <p>Counter: {counter}</p>
      <button onClick={increment}>Increment</button>
    </div>
  );
};

const mapStateToProps = state => ({
  counter: state.counter
});

const mapDispatchToProps = dispatch => ({
  increment: () => dispatch({ type: 'INCREMENT' })
});

export default connect(mapStateToProps, mapDispatchToProps)(Counter);