HarmonyOS 鸿蒙Next 接口请求报错Cannot store property of null or undefined

HarmonyOS 鸿蒙Next 接口请求报错Cannot store property of null or undefined
接口封装get方法如下:

get<T>(url: string, param: object | null, type: string): Promise<ResponseResult<T>> {
    let uri = WebUtils.getParam(url);
    let uriMap = uri.queryMap;
    uriMap.forEach((value, key) => {
        this.map.set(key, value);
    })
    params_type = type;
    const errorData = [] as T;
    let serverData: ResponseResult<T> = new ResponseResult(errorData);

    return apiClient.get(url, { params: param })
        .then((response: AxiosResponse) => {
            serverData = response.data;
            return serverData;
        })
        .catch((error: AxiosError) => {
            serverData.errmsg = error.message;
            return serverData;
        })
}

export class ResponseResult<T>{

/**
 * Code returned by the network request: success, fail.
 */
errno: number;

/**
 * Message returned by the network request.
 */
errmsg: string | Resource;

/**
 * Data returned by the network request.
 */
data: T;

constructor(data:T) {
    this.errno = -1;
    this.errmsg = '';
    this.data = data;
}

}

调用如下:

logout(): Promise<ResponseResult<User>> {
    return new Promise((resolve: Function) => {
        let url = `${NetConstant.LOGIN_OUT}`;
        let request = new NewRequest(NetConstant.BASE_URL_TYPE1);
        request.requestUse();
        request.get<User>(url, null, CommonConstants.TYPE_USER).then((data: ResponseResult<User>) => {

        })
    })
}

因为接口返回结果是:

{
    "errno": 0,
    "errmsg": "退出成功"
}

导致出现了如下报错Cannot store property of null or undefined

如何修改