code: public Node insertBefore(Node newChild, Node refChild) throws DOMException
    {
  
      error(XMLErrorResources.ER_FUNCTION_NOT_SUPPORTED);  //"insertBefore not supported!");
  
      return null;
    }
docs: Unimplemented. See org.w3c.dom.Node
  
  @param newChild New child node to insert
  @param refChild Insert in front of this child
  
  @return null
  
  @throws DOMException