code: protected int returnNextNode(int nextNode)
    {
  
      if (DTM.NULL != nextNode)
      {
        m_pos++;
      }
  
      m_lastFetched = nextNode;
  
      if (DTM.NULL == nextNode)
        m_foundLast = true;
  
      return nextNode;
    }
docs: Bottleneck the return of a next node, to make returns
  easier from nextNode().
  
  @param nextNode The next node found, may be null.
  
  @return The same node that was passed as an argument.