code: public static String valueOf(String namespace, String localPart){
          return StringUtil.isEmpty(namespace) ? localPart : '{'+namespace+'}'+localPart;
      }
docs: Returns string representation as <a href="http://jclark.com/xml/xmlns.htm">defined</a> by James Clark.
  <p>
  This is same as {@code String} returned by {@link javax.xml.namespace.QName#toString()}.
  
  @param namespace namespace, can be null
  @param localPart localpart
  
  @return clarkName