void Start(){	AssetBundleManager manager = AssetBundleManager.Instance;	manager.Init(() =>    {        LoadObjects();    });}void LoadObjects(){    manager.Load("Assets.Prefabs.Sphere.prefab", (a) =>    {        GameObject go = a.Instantiate(); //自动管理：当go被Destroy时，AB会被释放回收    });    manager.Load("Assets.my_txture.png", (a) =>    {    	// a.Retain();	//强制引用计数加一    	// a.Release();	//引用计数减一    	Texture tex = a.Require(this); //自动管理：当this被Destroy时，AB会被释放回收    });}