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Under utils/common.py, 

TIMESTAMP_FORMAT_MILLIS = '%Y-%m-%dT%H:%M:%S.%fZ'

The %f produces time with microseconds, for example: 2020-03-18T19:43:18.115783Z.


However, when interacting the AWS s3 and sns apis, I receive DateTimes like this:

2020-03-02T22:32:13.240Z
i.e. milliseconds. 

This seems like a simple change to the utils. TIMESTAMP_FORMAT_MILLIS is named as if it should be millis as well. This is seems like a simple change. Is there a reason it should be microseconds?
sns_error_to_dead_letter_queue(subscriber['SubscriptionArn'], req_data, str(exc))
                return make_error(message=str(exc), code=400)
        elif subscriber['Protocol'] in ['http', 'https']:
            msg_type = (req_data.get('Type') or ['Notification'])[0]
            try:
                message_body = create_sns_message_body(subscriber, req_data)
            except Exception as exc:
                return make_error(message=str(exc), code=400)
            try:
                response = requests.post(
                    subscriber['Endpoint'],
                    headers={
                        'Content-Type': 'text/plain',
                        
                        
                        'x-amz-sns-message-type': msg_type,
                        'x-amz-sns-topic-arn': subscriber['TopicArn'],
                        'x-amz-sns-subscription-arn': subscriber['SubscriptionArn'],
                        'User-Agent': 'Amazon Simple Notification Service Agent'
                    },
                    data=message_body,
                    verify=False
                )
                response.raise_for_status()
            except Exception as exc:
                sns_error_to_dead_letter_queue(subscriber['SubscriptionArn'], req_data, str(exc))
                return make_error(message=str(exc), code=400)
        else:
            LOGGER.warning('Unexpected protocol "%s" for SNS subscription' % subscriber['Protocol'])
def do_create_topic(topic_arn):