code: def render(self, engine, context):
          
          # We avoid use of the ternary operator for Python 2.4 support.
          def get_unicode(node):
              if type(node) is unicode:
                  return node
              return node.render(engine, context)
          parts = map(get_unicode, self._parse_tree)
          s = ''.join(parts)
  
          return unicode(s)
docs: Returns: a string of type unicode.