add another background image to change background during playing game <pre><code>func createBackgrounds() { for i in 0...2 { let bg = SKSpriteNode(imageNamed: "BG Day") bg.name = "BG" bg.zPosition = 0; bg.anchorPoint = CGPoint(x: 0.5, y: 0.5) bg.position = CGPoint(x: CGFloat(i) * bg.size.width, y: 0) self.addChild(bg) } } </code></pre> <p>If I want to add another background image after 2 minutes to <code>BG Night</code>, how can I write coding in swift 2?</p>