code: def _build_versioned_url(self, url):
          
          return '{}/v{}{}'.format(self.host, str(self._version), url)
docs: Subclass this function for your own needs.
             Or just pass the version as part of the URL
             (e.g. client._('/v3'))
          :param url: URI portion of the full URL being requested
          :type url: string
          :return: string