code: def url_for(*args, **kw):
          self, target, args = args[0], args[1], list(args[2:])
          query = kw.pop('_query', None)
          relative = kw.pop('_relative', False)
          url = build_url(self._context, target, args, kw)
          if query:
              if isinstance(query, dict):
                  query = sorted(query.items())
              query_part = urllib.urlencode(query)
              query_sep = '&' if '?' in url else '?'
              url = url + query_sep + query_part
          if relative:
              return url
          else:
              return urlparse.urljoin(self.application_uri, url)