Then your API will (let's imagine):

* Send the invoice to some customer of the external developer.
* Collect the money.
* Send a notification back to the API user (the external developer).
    * This will be done by sending a POST request (from *your API*) to some *external API* provided by that external developer (this is the "callback").

## The normal **FastAPI** app

		return v, ok
	}
	return cache.iamUserPolicyMap.Load(name)
}

// GroupNotificationHandler - updates in-memory cache on notification of
// change (e.g. peer notification for object storage and etcd watch
// notification).
func (store *IAMStoreSys) GroupNotificationHandler(ctx context.Context, group string) error {
	cache := store.lock()
	defer store.unlock()

// This list should be kept alphabetically sorted, do not hastily edit.
var resourceList = []string{
	"acl",
	"cors",
	"delete",
	"encryption",
	"legal-hold",
	"lifecycle",
	"location",
	"logging",
	"notification",
	"partNumber",
	"policy",
	"requestPayment",
	"response-cache-control",
	"response-content-disposition",
	"response-content-encoding",
	"response-content-language",
	"response-content-type",

	return makeTestTargetURL(endPoint, bucketName, objectName, url.Values{})
}

// return URL for inserting bucket notification.
func getPutNotificationURL(endPoint, bucketName string) string {
	queryValue := url.Values{}
	queryValue.Set("notification", "")
	return makeTestTargetURL(endPoint, bucketName, "", queryValue)
}

// return URL for inserting bucket policy.

		}
	}

	return nil
}

// To obtain a nats connection from args.
func (n NATSArgs) connectNats() (*nats.Conn, error) {
	connOpts := []nats.Option{nats.Name("Minio Notification"), nats.MaxReconnects(-1)}
	if n.Username != "" && n.Password != "" {
		connOpts = append(connOpts, nats.UserInfo(n.Username, n.Password))
	}
	if n.UserCredentials != "" {

 * requested entries may be evicted on each cache modification.
 *
 * <p>If {@link #expireAfterWrite expireAfterWrite} or {@link #expireAfterAccess expireAfterAccess}
 * is requested entries may be evicted on each cache modification, on occasional cache accesses, or
 * on calls to {@link Cache#cleanUp}. Expired entries may be counted by {@link Cache#size}, but will

    TF_Status* status) {
  tensorflow::EagerContext* context =
      tensorflow::ContextFromInterface(tensorflow::unwrap(ctx));
  auto collective_executor_handle = context->GetCollectiveExecutorHandle();
  tensorflow::Notification done;
  collective_executor_handle->get()->remote_access()->CheckPeerHealth(
      task, timeout_in_ms, [&done, status](const Status& s) {
        status->status = s;
        done.Notify();
      });

	queueDirComment   = `staging dir for undelivered messages e.g. '/home/events'`
	queueLimitComment = `maximum limit for undelivered messages, defaults to '100000'`
)

// Help template inputs for all notification targets
var (
	HelpWebhook = config.HelpKVS{
		config.HelpKV{
			Key:         target.WebhookEndpoint,
			Description: "webhook server endpoint e.g. http://localhost:8080/minio/events",
			Type:        "url",

            }
            if (logger.isInfoEnabled()) {
                logger.info("[CRAWL INFO] {}", buf);
            }

            // notification
            try {
                crawler.sendMail(infoMap);
            } catch (final Exception e) {
                logger.warn("Failed to send a mail.", e);
            }

        }
    }

		Description:    "The transition storage class was not found",
		HTTPStatusCode: http.StatusNotFound,
	},

	// Bucket notification related errors.
	ErrEventNotification: {
		Code:           "InvalidArgument",
		Description:    "A specified event is not supported for notifications.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrARNNotification: {
		Code:           "InvalidArgument",