code: public void appendNodes(NodeVector nodes)
    {
  
      if (!m_mutable)
        throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NODESETDTM_NOT_MUTABLE, null)); //"This NodeSetDTM is not mutable!");
  
      super.appendNodes(nodes);
    }
docs: Append the nodes to the list.
  
  @param nodes The nodes to be appended to this node set.
  @throws RuntimeException thrown if this NodeSetDTM is not of
  a mutable type.