private static void NormalizeBounds(ref MarkupRange bounds)
        {
            bool cloned = false;

            if (bounds.Start.IsRightOf(bounds.End))
            {
                if (!cloned)
                {
                    cloned = true;
                    bounds = bounds.Clone();
                }
                bounds.Normalize();
            }

            MarkupContext ctx = bounds.Start.Right(false);
            while (ctx.Context == _MARKUP_CONTEXT_TYPE.CONTEXT_TYPE_EnterScope
                && ElementFilters.IsBlockElement(ctx.Element))
            {
                if (!cloned)
                {
                    cloned = true;
                    bounds = bounds.Clone();
                }
                bounds.Start.Right(true);
                bounds.Start.Right(false, ctx);
            }
        }