HarmonyOS Video 怎么添加请求头？

import { media } from '@kit.MediaKit';

let player = await media.createAVPlayer();
let headers: Record<string, string> = {"User-Agent" : "User-Agent-Value"};
let mediaSource : media.MediaSource = media.createMediaSourceWithUrl("http://xxx",  headers);
let playStrategy : media.PlaybackStrategy = {preferredWidth: 1, preferredHeight: 2, preferredBufferDuration: 3, preferredHdr: false};
player.setMediaSource(mediaSource, playStrategy);