SceneKit macOS 10.14 Beta 2 to Beta 3 API Differences

SCNPhysicsWorld.h
Declaration
From@property (atomic, assign, nullable) id<SCNPhysicsContactDelegate> contactDelegate
To@property (atomic, weak, nullable) id<SCNPhysicsContactDelegate> contactDelegate

SCNSceneRenderer.h
Declaration
From@property (nonatomic, assign, nullable) id<SCNSceneRendererDelegate> delegate
To@property (nonatomic, weak, nullable) id<SCNSceneRendererDelegate> delegate