The process that happens when your API app calls the *external API* is named a "callback". Because the software that the external developer wrote sends a request to your API and then your API *calls back*, sending a request to an *external API* (that was probably created by the same developer).

4.  Code contributions require signing a Google CLA.

API changes
-----------

We make changes to Guava's public [APIs][], including adding new APIs, very
carefully. Because of this, if you're interested in seeing a new feature in
Guava, the best approach is to create an [issue][] (or comment on an existing
issue if there is one) requesting the feature and describing specific use cases
for it.

      <groupId>org.apache.velocity</groupId>
      <artifactId>velocity-engine-core</artifactId>
      <version>2.3</version>
      <type>jar</type>
      <scope>compile</scope>
    </dependency>

    <!-- Mail sending -->
    <dependency>
      <groupId>javax.mail</groupId>
      <artifactId>mail</artifactId>
      <version>1.4</version>
      <type>jar</type>
      <scope>compile</scope>
    </dependency>

an Identity Management Plugin webhook. When configured, this plugin enables the `AssumeRoleWithCustomToken` STS API extension. A user or application can now present a token to the `AssumeRoleWithCustomToken` API, and MinIO verifies this token by sending it to the Identity Management Plugin webhook. This plugin responds with some information and MinIO is able to generate temporary STS credentials to interact with object storage.

The authentication flow is similar to that of OpenID, however...

    val requestHeaders = http2HeadersList(request)
    stream = http2Connection.newStream(requestHeaders, hasRequestBody)
    // We may have been asked to cancel while creating the new stream and sending the request
    // headers, but there was still no stream to close.
    if (canceled) {
      stream!!.closeLater(ErrorCode.CANCEL)
      throw IOException("Canceled")
    }

			/// Enable keep-alive
			{
				_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1)

				// The time (in seconds) the connection needs to remain idle before
				// TCP starts sending keepalive probes
				_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPIDLE, 15)

				// Number of probes.
				// ~ cat /proc/sys/net/ipv4/tcp_keepalive_probes (defaults to 9, we reduce it to 5)

Alerting with prometheus is two step process. First we setup alerts in Prometheus server and then we need to send alerts to the AlertManager.

 * doesn't include the motivating request's HTTP headers or even its full URL; only the target
 * server's hostname is sent to the proxy.
 *
 * Prior to sending any CONNECT request OkHttp always calls the proxy authenticator so that it may
 * prepare preemptive authentication. OkHttp will call [authenticate] with a fake `HTTP/1.1 407

/**
 * This class simplifies communication for protocols that support
 * multiplexing requests. It encapsulates a stream and some protocol
 * knowledge (provided by a concrete subclass) so that connecting,
 * disconnecting, sending, and receiving can be syncronized
 * properly. Apparatus is provided to send and receive requests
 * concurrently.
 */

public abstract class Transport implements Runnable {

    static int id = 0;

	errFatal(remoteConn.WaitForConnect(context.Background()))
	const testPayload = "Hello Grid World!"

	gotResp := make(chan struct{})
	go func() {
		start := time.Now()
		t.Log("Roundtrip: sending request")
		resp, err := remoteConn.Request(context.Background(), handlerTest, []byte(testPayload))
		t.Log("Roundtrip:", time.Since(start), resp, err)
		gotResp <- struct{}{}
	}()
	<-gotCall