static void OnRepeatPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CircleText circleText = d as CircleText;

            if (circleText == null)
            {
                return;
            }

            if (e.NewValue == e.OldValue || e.NewValue == null)
            {
                return;
            }

            circleText.Update();
        }
        static void OnFontSizePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CircleText circleText = d as CircleText;

            if (circleText == null)
            {
                return;
            }

            if (MathUtility.IsEqualFuzzy((double)e.NewValue, (double)e.OldValue) || e.NewValue == null)
            {
                return;
            }

            circleText.Update();
        }