code: public Node removeNamedItemNS(String namespaceURI, String localName)
            throws DOMException
    {
      throw new DTMException(DTMException.NO_MODIFICATION_ALLOWED_ERR);
    }
docs: Removes a node specified by local name and namespace URI. A removed
  attribute may be known to have a default value when this map contains
  the attributes attached to an element, as returned by the attributes
  attribute of the <code>Node</code> interface. If so, an attribute
  immediately appears containing the default value as well as the
  corresponding namespace URI, local name, and prefix when applicable.
  <br>HTML-only DOM implementations do not need to implement this method.
  
  @param namespaceURI The namespace URI of the node to remove.
  @param localName The local name of the node to remove.
  
  @return The node removed from this map if a node with such a local
  name and namespace URI exists.
  @exception DOMException
  NOT_FOUND_ERR: Raised if there is no node with the specified
  <code>namespaceURI</code> and <code>localName</code> in this map.
  <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
  @since DOM Level 2