/// <summary>
        /// Draw graphics object
        /// </summary>
        public override void Draw(DrawingContext drawingContext)
        {
            drawingContext.DrawRectangle(
                null,
                new Pen(Brushes.White, ActualLineWidth),
                Rectangle);

            var dashStyle = new DashStyle();

            dashStyle.Dashes.Add(5);

            var dashedPen = new Pen(Brushes.Black, ActualLineWidth)
            {
                DashStyle = dashStyle
            };

            var animation = new DoubleAnimation
            {
                BeginTime      = new TimeSpan(0, 0, 0),
                RepeatBehavior = RepeatBehavior.Forever,
                From           = 0,
                To             = 20
            };

            dashStyle.BeginAnimation(DashStyle.OffsetProperty, animation);

            drawingContext.DrawRectangle(
                null,
                dashedPen,
                Rectangle);
        }