function updateDirtyRange( bookmark, dirtyRange, checkEnd ) {
var serializable = bookmark.serializable,
container = dirtyRange[ checkEnd ? 'endContainer' : 'startContainer' ],
function updateDirtyRange( bookmark, dirtyRange, checkEnd ) {
var serializable = bookmark.serializable,
container = dirtyRange[ checkEnd ? 'endContainer' : 'startContainer' ],