code: def write_success_response(self, result):
      
      response = self.make_success_response(result)
      now = time.time()
      spent = now - self.basehandler_starttime
      response[constants.RESPONSE_KEY_EXECUTION_TIME] = spent
      self.write_json_response(response)
docs: Result may be a python dictionary, array or a primitive type
      that can be converted to JSON for writing back the result.