Then, the browser will send an HTTP `OPTIONS` request to the `:80`-backend, and if the backend sends the appropriate headers authorizing the communication from this different origin (`http://localhost:8080`) then the `:8080`-browser will let the JavaScript in the frontend send its request to the `:80`-backend.

To achieve this, the `:80`-backend must have a list of "allowed origins".

```

## Example

MinIO exposes a custom S3 STS API endpoint as `Action=AssumeRoleWithCertificate`. A client has to send an HTTP `POST` request to `https://<host>:<port>?Action=AssumeRoleWithCertificate&Version=2011-06-15`. Since the authentication and authorization happens via X.509 certificates the client has to send the request over **TLS** and has to provide
a client certificate.

  override fun send(text: String): Boolean = send(text.encodeUtf8(), OPCODE_TEXT)

  override fun send(bytes: ByteString): Boolean = send(bytes, OPCODE_BINARY)

  @Synchronized private fun send(
    data: ByteString,
    formatOpcode: Int,
  ): Boolean {
    // Don't send new frames after we've failed or enqueued a close frame.

So, let's review it from that simplified point of view:

* The user types the `username` and `password` in the frontend, and hits `Enter`.
* The frontend (running in the user's browser) sends that `username` and `password` to a specific URL in our API (declared with `tokenUrl="token"`).
* The API checks that `username` and `password`, and responds with a "token" (we haven't implemented any of this yet).

    }

    /**
     * Calculate average send latency in microseconds
     *
     * @return average send latency
     */
    public double getAverageSendLatencyMicros() {
        long sends = rdmaSends.get();
        if (sends == 0) {
            return 0.0;
        }
        return totalSendTime.get() / (double) sends / 1000.0; // Convert to microseconds
    }

    /**

	return nil
}

// CommitBinary - sends commit binary message to remote peers.
func (client *peerRESTClient) CommitBinary(ctx context.Context) error {
	respBody, err := client.callWithContext(ctx, peerRESTMethodCommitBinary, nil, nil, -1)
	if err != nil {
		return err
	}
	defer xhttp.DrainBody(respBody)
	return nil
}

// SignalService - sends signal to peer nodes.

    @Test
    @DisplayName("setLength(): SMB2 path sends Smb2SetInfoRequest")
    void setLength_smb2_sendsSetInfo() throws Exception {
        SmbRandomAccessFile raf = newInstance("rw", true, false, false);
        SmbFileHandleImpl fh = (SmbFileHandleImpl) getField(raf, "handle");
        SmbTreeHandleImpl tree = fh.getTree();
        // do not actually perform network call

		desc: prometheus.NewDesc("minio_stats", "Statistics exposed by MinIO server", nil, nil),
	}
}

// minioCollector is the Custom Collector
type minioCollector struct {
	desc *prometheus.Desc
}

// Describe sends the super-set of all possible descriptors of metrics
func (c *minioCollector) Describe(ch chan<- *prometheus.Desc) {
	ch <- c.desc
}

// Collect is called by the Prometheus registry when collecting metrics.

            }
        }
    }

    /**
     * Monitors active registrations and sends heartbeats.
     */
    private void monitorRegistrations() {
        for (WitnessRegistration registration : registrations.values()) {
            if (registration.getState() == WitnessRegistrationState.REGISTERED) {
                // Send periodic heartbeat
                sendHeartbeat(registration);
            }
        }

    frame.writeByte(Http2.TYPE_HEADERS)
    frame.writeByte(FLAG_END_HEADERS or FLAG_END_STREAM)
    frame.writeInt(expectedStreamId and 0x7fffffff)
    frame.writeAll(headerBytes)

    // Check writer sends the same bytes.
    assertThat(sendHeaderFrames(true, sentHeaders)).isEqualTo(frame)
    reader.nextFrame(
      requireSettings = false,
      object : BaseTestHandler() {
        override fun headers(