             Draw.drawCircle(context, center: curves[0].points[3], radius: 3, offset: offset)
             Draw.drawCircle(context, center: B, radius: 3, offset: offset);
         })
-        let demo3 = Demo(controlPoints: controlPoints, drawFunction: { (context: CGContext, demo: Demo) in
+        let demo3 = Demo(controlPoints: controlPoints,
+                         drawFunction: { (context: CGContext, demo: Demo) in
             let curve = CubicBezier( p0: self.draggables[0].bkLocation,
                                      p1: self.draggables[1].bkLocation,
                                      p2: self.draggables[2].bkLocation,

        }
    }
    
    func addDraggable(initialLocation location: CGPoint, radius: CGFloat) -> Draggable {
        let draggable = Draggable(initialLocation: location, radius: radius)
        draggable.delegate = self
        self.draggables.append(draggable)
        return draggable
    }
    
    override func mouseDown(with event: NSEvent) {

            Draw.drawSkeleton(context, curve: curve)
            Draw.drawCurve(context, curve: curve)
        })
        let demo2 = Demo(controlPoints: [],
                         drawFunction: { (context: CGContext, demo: Demo) in
            let p1 = BKPoint(x: 110, y: 50)
            let B = BKPoint(x: 50, y: 80)
            let p3 = BKPoint(x:135, y:100)
