var cancel context.CancelFunc
		ctx, cancel = context.WithTimeout(ctx, defaultSingleRequestTimeout)
		defer cancel()
	}
	// Send request
	if err := m.send(msg); err != nil {
		return nil, err
	}
	if debugReqs {
		fmt.Println(m.MuxID, m.parent.String(), "SEND")
	}
	// Wait for response or context.
	select {
	case v, ok := <-ch:
		if !ok {
			return nil, ErrDisconnected
		}

    /**
     * @return true if the <b>debug</b> error level is enabled
     */
    boolean isDebugEnabled();

    /**
     * Send a message to the user in the <b>debug</b> error level.
     *
     * @param content
     */
    void debug(CharSequence content);

    /**
     * Send a message (and accompanying exception) to the user in the <b>debug</b> error level.<br>

	go func() {
		wg.Wait()
		defer xioutil.SafeClose(send)
		err := m.handleRequests(ctx, msg, send, handler, handlerIn)
		if err != nil {
			handlerErr.Store(err)
		}
	}()

	// Response sender goroutine...
	go func(outBlock <-chan struct{}) {
		wg.Wait()
		defer m.parent.deleteMux(true, m.ID)
		m.sendResponses(ctx, send, c, &handlerErr, outBlock)
	}(m.outBlock)

import org.dbflute.mail.send.SMailDeliveryDepartment;
import org.dbflute.mail.send.SMailPostalMotorbike;
import org.dbflute.mail.send.SMailPostalParkingLot;
import org.dbflute.mail.send.SMailPostalPersonnel;
import org.dbflute.mail.send.embedded.personnel.SMailDogmaticPostalPersonnel;
import org.dbflute.mail.send.embedded.receptionist.SMailConventionReceptionist;
import org.dbflute.mail.send.supplement.async.SMailAsyncStrategy;

///

## Await for messages and send messages

In your WebSocket route you can `await` for messages and send messages.

```Python hl_lines="48-52"
{!../../docs_src/websockets/tutorial001.py!}
```

You can receive and send binary, text, and JSON data.

## Try it

If your file is named `main.py`, run your application with:

    server.send(message3)
    clientListener.assertTextMessage(message3)

    // Empty client to server message.
    val message4 = ""
    client.send(message4)
    serverListener.assertTextMessage(message4)

    // Server to client message that shares context with message1.
    val message5 = message1 + message1
    server.send(message5)
    clientListener.assertTextMessage(message5)

import org.codelibs.fess.util.ComponentUtil;
import org.dbflute.mail.CardView;
import org.dbflute.mail.send.supplement.SMailPostingDiscloser;

public class NotificationHelper {
    private static final Logger logger = LogManager.getLogger(NotificationHelper.class);

    protected static final char LF = '\n';

    public void send(final CardView cardView, final SMailPostingDiscloser discloser) {
        sendToSlack(cardView, discloser);

This is normally called a **webhook**.

## Webhooks steps

The process normally is that **you define** in your code what is the message that you will send, the **body of the request**.

You also define in some way at which **moments** your app will send those requests or events.

}

/*
To clean up stale ztunnels

	we may need to ztunnel to send its (uid, bootid / boot time) to us
	so that we can remove stale entries when the ztunnel pod is deleted
	or when the ztunnel pod is restarted in the same pod (remove old entries when the same uid connects again, but with different boot id?)

	save a queue of what needs to be sent to the ztunnel pod and send it one by one when it connects.

    taskFaker.runTasks()
    client.listener.assertFailure(IOException::class.java, "source is closed")
    assertThat(client.webSocket!!.send("Hello!")).isFalse()
  }

  @Test
  fun socketClosedDuringMessageKillsWebSocket() {
    client2Server.source.close()
    assertThat(client.webSocket!!.send("Hello!")).isTrue()
    taskFaker.runTasks()
    client.listener.assertFailure(IOException::class.java, "source is closed")