'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.'

def add_ok_action(self, action_arn=None):

    if (not action_arn):
        return
    self.actions_enabled = 'true'
    self.ok_actions.append(action_arn)
