参数列表无法分配给参数类型列表

我遇到了一个我搞不清楚的错误。我从操作中调用服务,并用响应设置新的redux状态。但是,我得到以下错误:

错误:

The argument type 'List<Chat> (C:\flutter\bin\cache\pkg\sky_engine\lib\core\list.dart)' can't be assigned to the parameter type 'List<Chat> (C:\flutter\bin\cache\pkg\sky_engine\lib\core\list.dart)'.

行动:

class GetChatRequest {}

class GetChatSuccess {
  final List<Chat> history;

  GetChatSuccess(this.history);
}

class GetChatFailure {
  final String error;

  GetChatFailure(this.error);
}

final Function getLastChatMessages = () {
  return (Store<AppState> store) {
    var chatService = new ChatService(store);

    store.dispatch(new GetChatRequest());
    chatService.getLast50Messages().then((history) {
      store.dispatch(new GetChatSuccess(history));
    });
  };
};

服务:

Future<List<Chat>> getLast50Messages() async {
    final response = await webClient.get('xxxx');
    return response['data'].map<Chat>((e) => new Chat.fromJSON(e)).toList();
  }