         }
         self.setNeedsDisplay()
     }
-
+    
+    // MARK:- Drawing
+    
     override func draw(_ rect: CGRect) {
         for line in activeLines.values {
             line.stroke()
         }
 
-        for line in lines{
+        for line in lines {
             line.stroke()
         }
     }


class DrawingView: UIView {

    let lineWidth = CGFloat(1.0)
    var activeLines = [UITouch: UIBezierPath]()
    var lines = [UIBezierPath]()

    override init(frame: CGRect) {
        super.init(frame: frame)

    func setup(){
        isMultipleTouchEnabled = true
    }
    
    // MARK:- Touch handling
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        self.isMultipleTouchEnabled = true
        for touch in touches {
