public static Task FadeToAsync(this VisualElement element, double value, AnimationCurve curve = null) => element.AnimateAsync <OpacityTransition>(() => element.Opacity = value);
public static async Task FadeToAsync(this VisualElement element, double value, AnimationCurve?curve = null) => await element.AnimateAsync <OpacityTransition>(() => element.Opacity = value).ConfigureAwait(false);