IsInDesignMode for Silverlight

Here is the proper way to check for IsInDesignMode for Silverlight which works for both Blend and Visual Studio.

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public class Bootstrapper
{
    private static bool? _isInDesignMode = null;

    /// <summary>
    /// Returns a boolean value whether the code is currently running in design-mode.
    /// This check works for both Blend and Visual Studio. 
    /// DesignerProperties.GetIsInDesignMode() that many uses only works in Blend.
    /// </summary>
    public static bool IsInDesignMode
    {
        get
        {
            if (_isInDesignMode == null)
            {
                // At design-time, Application.Current is "Application".
                if (Application.Current.GetType() == typeof(System.Windows.Application))
                {
                    _isInDesignMode = true;
                }
                else
                {
                    _isInDesignMode = false;
                }
            }

            return _isInDesignMode.Value;
        }
    }
}