code: public final void revert() {
  
          if (tagged) {
  
              // Remove the added entries
              final Iterator<T> addedIt = added.iterator();
              while (addedIt.hasNext()) {
                  final Object entry = addedIt.next();
                  list.remove(entry);
                  addedIt.remove();
              }
  
              // Add the removed entries
              final Iterator<T> removedIt = deleted.iterator();
              while (removedIt.hasNext()) {
                  final T entry = removedIt.next();
                  list.add(entry);
                  removedIt.remove();
              }
  
          }
  
      }
docs: Roll back all changes made since construction. WARNING: The position of the elements is <b>not</b> guaranteed to be the same again!
  This is the same function ad {@link #revertToTag()}. If the list is not in tag mode ( this means {@link #isTagged()} returns
  <code>true</code>) this method will do nothing.