public static void ChangeElementTagIds(MshtmlMarkupServices markupServices, MarkupRange selection, _ELEMENT_TAG_ID[] tagBefore, _ELEMENT_TAG_ID tagAfter)
        {
            HtmlStyleHelper htmlStyleHelper = new HtmlStyleHelper(markupServices);

            int parentStartDiff = 0;
            MarkupRange rangeToChange;
            bool selectionStartedEmpty = selection.IsEmpty();
            if (selectionStartedEmpty)
            {
                // Operate on parent block element
                rangeToChange = markupServices.CreateMarkupRange(selection.ParentBlockElement());
                parentStartDiff = selection.Start.MarkupPosition - rangeToChange.Start.MarkupPosition;
            }
            else
            {
                rangeToChange = selection;

                // If expanding the selection would not include any new text, then expand it.
                // <h1>|abc|</h1> --> |<h1>abc</h1>|
                rangeToChange.MoveOutwardIfNoText();
            }

            IHTMLElementFilter[] filters = new IHTMLElementFilter[tagBefore.Length];

            for (int i = 0; i < tagBefore.Length; i++)
                filters[i] = ElementFilters.CreateTagIdFilter(markupServices.GetNameForTagId(tagBefore[i]));

            IHTMLElement[] elements = rangeToChange.GetElements(ElementFilters.CreateCompoundElementFilter(filters), false);
            foreach (IHTMLElement element in elements)
            {
                MarkupRange elementRange = markupServices.CreateMarkupRange(element);

                int startPositionDiff = rangeToChange.Start.MarkupPosition - elementRange.Start.MarkupPosition;
                int endPositionDiff = rangeToChange.End.MarkupPosition - elementRange.End.MarkupPosition;

                // @RIBBON TODO: Appropriately preserve element attributes when changing tag ids?
                MarkupRange newElementRange = markupServices.CreateMarkupRange(htmlStyleHelper.WrapRangeInSpanElement(tagAfter, null, elementRange));
                markupServices.RemoveElement(element);

                MarkupPointer startPointer = rangeToChange.Start.Clone();
                startPointer.MoveToMarkupPosition(startPointer.Container, newElementRange.Start.MarkupPosition + startPositionDiff);
                if (startPointer.IsLeftOf(rangeToChange.Start))
                    rangeToChange.Start.MoveToPointer(startPointer);

                MarkupPointer endPointer = rangeToChange.End.Clone();
                endPointer.MoveToMarkupPosition(endPointer.Container, newElementRange.End.MarkupPosition + endPositionDiff);
                if (endPointer.IsLeftOf(elementRange.End))
                    rangeToChange.End.MoveToPointer(endPointer);
            }

            if (selectionStartedEmpty)
            {
                selection.Start.MoveToMarkupPosition(selection.Start.Container, rangeToChange.Start.MarkupPosition + parentStartDiff);
                selection.Collapse(true);
            }
        }
        internal bool Restore(MarkupRange selection, MarkupRange bounds)
        {
            if (initialMarkup == null)
                return false;

            NormalizeBounds(ref bounds);
            /*
                        if (initialMarkup != bounds.HtmlText)
                        {
                            Trace.Fail("Unexpected markup");
                            Trace.WriteLine(initialMarkup);
                            Trace.WriteLine(bounds.HtmlText);
                            return false;
                        }
            */

            selection.Start.MoveToPointer(bounds.Start);

            if (movesRight == int.MaxValue)
            {
                selection.Start.MoveToPointer(bounds.End);
            }
            else
            {
                for (int i = 0; i < movesRight; i++)
                {
                    selection.Start.Right(true);
                }
            }

            for (int i = 0; i < charsLeft; i++)
            {
                selection.Start.MoveUnit(_MOVEUNIT_ACTION.MOVEUNIT_PREVCHAR);
            }

            selection.Collapse(true);
            selection.ToTextRange().select();

            Debug.Assert(bounds.InRange(selection, true), "Selection was out of bounds");

            return true;
        }