docs: def to_xml(self, root):
          '''
          Returns a DOM element contaning the XML representation of the
          ExtensibleXMLiElement
          @param root:Element Root XML element.
          @return: Element
          '''
          if not len(self.__custom_elements):
              return
  
          for uri, tags in self.__custom_elements.items():
              prefix, url = uri.split(":", 1)
              for name, value in tags.items():
                  self.__createElementNS(root, url, prefix + ":" + name, value)
  
          return root