code: def add_ok_action(self, action_arn=None):
          
          if not action_arn:
              return
          self.actions_enabled = 'true'
          self.ok_actions.append(action_arn)
docs: Adds an ok action, represented as an SNS topic, to this alarm. What
          to do when the ok state is reached.
  
          :type action_arn: str
          :param action_arn: SNS topics to which notification should be 
                             sent if the alarm goes to state INSUFFICIENT_DATA.