You can yield until asynchronous operation continues, or manually check whether it's done
(isDone) or progress (progress).
See Also: SceneManager.LoadSceneAsync, AssetBundle.LoadAssetAsync, Resources.LoadAsync.
|allowSceneActivation||Allow Scenes to be activated as soon as it is ready.|
|completed||Event that is invoked upon operation completion. An event handler that is registered in the same frame as the call that creates it will be invoked next frame, even if the operation is able to complete synchronously. If a handler is registered after the operation has completed and has already invoked the complete event, the handler will be called synchronously.|