src/vs/platform/userDataSync/common/userDataSyncBackupStoreService.ts/UserDataSyncBackupStoreService/resolveContent
class UserDataSyncBackupStoreService:	async resolveContent(resource: SyncResource, ref?: string): Promise<string | null> {
		if (!ref) {
			const refs = await this.getAllRefs(resource);
			if (refs.length) {
				ref = refs[refs.length - 1].ref;
			}
		}
		if (ref) {
			const file = joinPath(this.environmentService.userDataSyncHome, resource, ref);
			const content = await this.fileService.readFile(file);
			return content.value.toString();
		}
		return null;
	}