* noOpBackup in two cases:
* - setValue not called on entry
* - or entry does not exist and no add operation is done.
*/
private boolean noOpBackup(Map.Entry entry) {
final MapEntrySimple mapEntrySimple = (MapEntrySimple) entry;
return !mapEntrySimple.isModified() || (oldValue == null && entry.getValue() == null);
}