App Development with Swift. Lesson 3A.2 Introduction to SceneKit

Hi, I study Augmented Reality and have some questions. On page 459 author of this textbook say to add a new node with next code:


let node = SCNNode()
node.position = SCNVector3(0.0, 0.2, 0.0)


Please tell me where, in what place, I should to insert this code? Into viewDidLoad method or other?