code: public NodeSetDTM mutableNodeset()
    {
      NodeSetDTM mnl;
  
      if(m_obj instanceof NodeSetDTM)
      {
        mnl = (NodeSetDTM) m_obj;
      }
      else
      {
        mnl = new NodeSetDTM(iter());
        setObject(mnl);
        setCurrentPos(0);
      }
  
      return mnl;
    }
docs: Cast result object to a mutableNodeset.
  
  @return The nodeset as a mutableNodeset