/// <summary>
/// IsEnabledProperty property changed handler.
/// </summary>
/// <param name="d">ContentControl that changed IsEnabled.</param>
/// <param name="e">DependencyPropertyChangedEventArgs.</param>
private static void OnIsEnabledPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ContentControl source = d as ContentControl;
Debug.Assert(source != null,
"The source is not an instance of ContentControl!");
Debug.Assert(typeof(bool).IsInstanceOfType(e.NewValue),
"The value is not an instance of bool!");
bool value = (bool)e.NewValue;
source.OnIsEnabledChanged(value);
}