code: def update(self, is_reserved=values.unset):
          
          data = values.of({'IsReserved': is_reserved, })
  
          payload = self._version.update(
              'POST',
              self._uri,
              data=data,
          )
  
          return ShortCodeInstance(
              self._version,
              payload,
              service_sid=self._solution['service_sid'],
              sid=self._solution['sid'],
          )
docs: Update the ShortCodeInstance
  
          :param bool is_reserved: Whether the short code should be reserved for manual assignment to participants only
  
          :returns: Updated ShortCodeInstance
          :rtype: twilio.rest.proxy.v1.service.short_code.ShortCodeInstance