/// <summary>
        /// Called once per iteration through the FrugalMap containing all cached default values
        /// for a given DependencyObject. This method promotes each of the defaults to locally-set.
        /// </summary>
        /// <param name="list"></param>
        /// <param name="key">The DP's global index</param>
        /// <param name="value">The cached default</param>
        private static void DefaultValueCachePromotionCallback(ArrayList list, int key, object value)
        {
            Freezable cachedDefault = value as Freezable;

            if (cachedDefault != null)
            {
                // The only way to promote a cached default is to fire its Changed event.
                cachedDefault.FireChanged();
            }
        }