code: def process(self, value, tag=None):
          
          content = Content(tag=tag, value=value)
          result = Core.process(self, content)
          return result
docs: Process (marshal) the tag with the specified value using the
          optional type information.
          @param value: The value (content) of the XML node.
          @type value: (L{Object}|any)
          @param tag: The (optional) tag name for the value.  The default is
              value.__class__.__name__
          @type tag: str
          @return: An xml node.
          @rtype: L{Element}