Touch me to impulse

GameScene.swift

// omitted
class GameScene: SKScene {
  // omitted
    override func didMoveToView(view: SKView) {
      // omitted
    }
    
    // This method is called when the user touches the screen
    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
      // we apply an impulse to the axis Y of 70
      player.physicsBody?.applyImpulse(CGVector(dx: 0.0, dy: 70.0))
    }
  // omitted
}