InitializeAR

We need a common entry point for iOS and Android to hook up to. Since the initialization of ARKit and ARCore is platform-specific, we will simply define an abstract method that each platform can override. You can do this by following these steps:

1. In the WhackABox project, open the Game.cs class.
2. Add the following InitializeAR() method to the class:

protected abstract void InitializeAR();

Since the class is itself abstract, we can also define methods as abstract. This means that this method must be implemented by any class that inherits from the Game class.