 		return instance
 	}()
 	
+	
+	// MARK: UICollectionView delegate/datasource
+	
 	func scrollViewDidScroll(scrollView: UIScrollView) {
 		if enablePropagationCounter < 0 {
 			return

		zoomLabel.text = String(format: "%.1f", model.zoom)
	}

	// MARK: button for zoom in
	
	lazy var zoomInButton: UIButton = {
		let instance = UIButton(type: .Custom)

		}
	}
	

	// MARK: Label that shows the current zoom factor
	
	lazy var zoomLabel: UILabel = {
		let instance = UILabel()
		instance.textColor = UIColor(white: 0.2, alpha: 1.0)
