https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

com um corpo JSON de:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

então *sua API* processará a fatura e, em algum momento posterior, enviará uma solicitação de callback para o `callback_url` (a *API externa*):

```
https://www.external.org/events/invoices/2expen51ve
```

fn, isDelegated)\n}\n\nfunction removeHandler(element, events, typeEvent, handler, delegationSelector) {\n  const fn = findHandler(events[typeEvent], handler, delegationSelector)\n\n  if (!fn) {\n    return\n  }\n\n  element.removeEventListener(typeEvent, fn, Boolean(delegationSelector))\n  delete events[typeEvent][fn.uidEvent]\n}\n\nfunction removeNamespacedHandlers(element, events, typeEvent, namespace) {\n  const storeElementEvent = events[typeEvent] || {}\n\n  for (const [handlerKey, event] of...

user  nginx;
worker_processes  auto;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '

           value: "image/*" # match objects with 'content-type', with all values starting with 'image/'

#    notify:
#      endpoint: "https://notify.endpoint" # notification endpoint to receive job status events
#      token: "Bearer xxxxx" # optional authentication token for the notification endpoint
#
#    retry:
#      attempts: 10 # number of retries for the job before giving up

import okio.ForwardingSource
import okio.Sink
import okio.Socket
import okio.Source
import okio.buffer

/**
 * Transmits a single HTTP request and a response pair. This layers connection management and events
 * on [ExchangeCodec], which handles the actual I/O.
 */
class Exchange(
  internal val call: RealCall,
  internal val eventListener: EventListener,
  internal val finder: ExchangeFinder,

user  nginx;
worker_processes  auto;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;

events {
    worker_connections  4096;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '

user  nginx;
worker_processes  auto;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;

events {
    worker_connections  4096;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '

			Queries("notification", "")
		// ListenNotification
		router.Methods(http.MethodGet).
			HandlerFunc(s3APIMiddleware(api.ListenNotificationHandler, noThrottleS3HFlag, traceHdrsS3HFlag)).
			Queries("events", "{events:.*}")
		// ResetBucketReplicationStatus - MinIO extension API
		router.Methods(http.MethodGet).
			HandlerFunc(s3APIMiddleware(api.ResetBucketReplicationStatusHandler)).
			Queries("replication-reset-status", "")

Normalmente, o processo é que **você define** em seu código qual é a mensagem que você irá mandar, o **corpo da sua requisição**.

Você também define de alguma maneira em quais **momentos** a sua aplicação mandará essas requisições ou eventos.

E os **seus usuários** definem de alguma forma (em algum painel por exemplo) a **URL** que a sua aplicação deve enviar essas requisições.

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package jcifs.internal.witness;

/**
 * Enumeration of SMB Witness Event Types as defined in MS-SWN specification.
 * These events represent different types of cluster state changes that clients
 * can be notified about.
 */
public enum WitnessEventType {
    /**
     * Resource state changed - general resource state modification
     */