private static void OnMinValueUpdate(DependencyObject obj, DependencyPropertyChangedEventArgs e)
        {
            CircularSlider slider = obj as CircularSlider;

            if (slider != null)
            {
                slider.Update();
            }
        }
        private static void OnValueUpdate(DependencyObject obj, DependencyPropertyChangedEventArgs e)
        {
            CircularSlider slider = obj as CircularSlider;

            if (slider != null)
            {
                if (slider.Value > slider.MaximumValue)
                {
                    slider.Value = slider.MaximumValue;
                }
                if (slider.Value < slider.MinimumValue)
                {
                    slider.Value = slider.MinimumValue;
                }
                slider.Update();
            }
        }