public void LoadAssetBundle()
 {
     if (bundle != null)
     {
         bundle.LoadAllAssets();
         status = AssetBundleDownloadingHandleStatus.AssetLoaded;
     }
 }
 public void UnloadAssetBundle()
 {
     if (bundle != null)
     {
         Resources.UnloadAsset(bundle);
         bundle = null;
         status = AssetBundleDownloadingHandleStatus.Unloaded;
     }
 }