notificationEventsErrorsTotalMD     = NewCounterMD(notificationEventsErrorsTotal, "Events that were failed to be sent to the targets")
	notificationEventsSentTotalMD       = NewCounterMD(notificationEventsSentTotal, "Total number of events sent to the targets")

	// global Trace system to send HTTP request/response
	// and Storage/OS calls info to registered listeners.
	globalTrace = pubsub.New[madmin.TraceInfo, madmin.TraceType](8)

	// global Listen system to send S3 API events to registered listeners
	globalHTTPListen = pubsub.New[event.Event, pubsub.Mask](0)

	// global console system to send console logs to
	// registered listeners

        "webhooks": {
            "new-subscription": {
                "post": {
                    "summary": "New Subscription",
                    "description": "When a new user subscribes to your service we'll send you a POST request with this\ndata to the URL that you register for the event `new-subscription` in the dashboard.",
                    "operationId": "new_subscriptionnew_subscription_post",
                    "requestBody": {

	webhookFailedMessagesMD = NewCounterMD(webhookFailedMessages,
		"Number of messages that failed to send",
		allWebhookLabels...)
	webhookQueueLengthMD = NewGaugeMD(webhookQueueLength,
		"Webhook queue length",
		allWebhookLabels...)
	webhookTotalMessagesMD = NewCounterMD(webhookTotalMessages,
		"Total number of messages sent to this target",
		allWebhookLabels...)
)

This includes, for example:

* Email notifications sent after performing an action:
    * As connecting to an email server and sending an email tends to be "slow" (several seconds), you can return the response right away and send the email notification in the background.
* Processing data:

        .build(),
    )

    val request =
      HttpRequest
        .newBuilder(server.url("/").toUri())
        .header("Accept", "text/plain")
        .build()

    val response = httpClient.send(request, BodyHandlers.ofString())
    assertThat(response.statusCode()).isEqualTo(200)
    assertThat(response.body()).isEqualTo("hello, Java HTTP Client")

    val recorded = server.takeRequest()

     * @param debugData only valid for HTTP/2; opaque debug data to send.
     */
    fun goAway(
      lastGoodStreamId: Int,
      errorCode: ErrorCode,
      debugData: ByteString,
    )

    /**
     * Notifies that an additional `windowSizeIncrement` bytes can be sent on `streamId`, or the
     * connection if `streamId` is zero.
     */
    fun windowUpdate(

            Doc(
                """
                By default, if no HTTP Authorization header is provided, required for
                OpenID Connect authentication, it will automatically cancel the request
                and send the client an error.

                If `auto_error` is set to `False`, when the HTTP Authorization header
                is not available, instead of erroring out, the dependency result will
                be `None`.

The spec also states that the `username` and `password` must be sent as form data (so, no JSON here).

### `scope` { #scope }

The spec also says that the client can send another form field "`scope`".

The form field name is `scope` (in singular), but it is actually a long string with "scopes" separated by spaces.

### Conditional Cache Hit
 
When cache flags require checking the cache results are still valid an early cacheConditionalHit event is
received followed by a cache hit or miss.  Critically in the cache hit scenario the server won’t send the response body.

The response will have non-null `cacheResponse` and `networkResponse`. The cacheResponse will be used as the top level
response only if the response code is HTTP/1.1 304 Not Modified.
 
 - CallStart