private static void AdjustMarkupRangeCore(MarkupRange range, int offset, int length, string currentText)
{
MarkupPointer start = range.Start;
MarkupPointer end = range.End;
if (offset > 0)
{
start.MoveToMarkupPosition(start.Container, start.MarkupPosition + offset);
}
if (length < (offset + currentText.Length))
{
end.MoveToMarkupPosition(start.Container, start.MarkupPosition + length);
}
}