code: def create_subscription(self, subscription):
          
          if subscription.subscription_id is not None:
              self._validate_uuid(subscription.subscription_id)
  
          if subscription.endpoint is not None:
              if subscription.endpoint.subscriber_id is not None:
                  self._validate_subscriber_id(
                      subscription.endpoint.subscriber_id)
  
              if subscription.endpoint.endpoint_id is not None:
                  self._validate_uuid(subscription.endpoint.endpoint_id)
  
          if subscription.channel is not None:
              self._validate_uuid(subscription.channel.channel_id)
  
          url = "/notification/v1/subscription"
          response = NWS_DAO().postURL(url, self._write_headers(),
                                       self._json_body(subscription.json_data()))
  
          if response.status != 201:
              raise DataFailureException(url, response.status, response.data)
  
          return response.status
docs: Create a new subscription
          :param subscription: the new subscription the client wants to create