code: def update(self, style_sheet=values.unset):
          
          data = values.of({'StyleSheet': serialize.object(style_sheet), })
  
          payload = self._version.update(
              'POST',
              self._uri,
              data=data,
          )
  
          return StyleSheetInstance(self._version, payload, assistant_sid=self._solution['assistant_sid'], )
docs: Update the StyleSheetInstance
  
          :param dict style_sheet: The JSON string that describes the style sheet object
  
          :returns: Updated StyleSheetInstance
          :rtype: twilio.rest.autopilot.v1.assistant.style_sheet.StyleSheetInstance