HarmonyOS 如何初始化一个泛型方法的返回值？

function get<T>(url: ESObject, param: Map<string, Object>,headers:HashMap<string,string | string[] | number | boolean | null>): Promise<T> { 
  return new Promise((resolve, reject) => { 
    let config: AxiosRequestConfig = {}; 
    config.url = url; 
    config.baseURL = config.baseURL; 
    config.params = param; 
    //设置请求头信息 
    this.setHeaders(config,headers) 
 
    axios.get<T, AxiosResponse<T>, null>(url, config) 
      .then((response: AxiosResponse<T>) => { 
        resolve(response.data); 
      }).catch(() => { 
      reject() 
    }) 
  }) 
}