'Sets an SNS topic to publish bounce or complaint notifications for
emails sent with the given identity as the Source. Publishing to topics
may only be disabled when feedback forwarding is enabled.
:type identity: string
:param identity: An email address or domain name.
:type notification_type: string
:param notification_type: The type of feedback notifications that will
be published to the specified topic.
Valid Values: Bounce | Complaint | Delivery
:type sns_topic: string or None
:param sns_topic: The Amazon Resource Name (ARN) of the Amazon Simple
Notification Service (Amazon SNS) topic.'

def set_identity_notification_topic(self, identity, notification_type, sns_topic=None):

    params = {'Identity': identity, 'NotificationType': notification_type}
    if sns_topic:
        params['SnsTopic'] = sns_topic
    return self._make_request('SetIdentityNotificationTopic', params)
