code: public Versioned<E> previous() {
          if(hasPrevious()) {
              E resultValue = _previousNode.getValue().getValue();
              _lastId = _previousNode.getValue().getId();
              _lastCall = LastCall.PREVIOUS;
              _nextNode = _previousNode;
              _isNextSet = true;
              _isPreviousSet = false;
              return new Versioned<E>(resultValue, _previousNode.getVersion());
          } else {
              throw new NoSuchElementException();
          }
      }
docs: /*
  (non-Javadoc)
  
  @see java.util.ListIterator#previous()