src/vs/platform/userDataSync/common/userDataSyncBackupStoreService.ts/UserDataSyncBackupStoreService/resolveContent
class UserDataSyncBackupStoreService:	async resolveContent(profile: IUserDataProfile, resourceKey: SyncResource, ref: string): Promise<string | null> {
		const folder = this.getResourceBackupHome(profile, resourceKey);
		const file = joinPath(folder, ref);
		try {
			const content = await this.fileService.readFile(file);
			return content.value.toString();
		} catch (error) {
			this.logService.error(error);
			return null;
		}
	}