def test():
    log = Path("log.txt")
    if log.is_file():
        os.remove(log)  # pragma: no cover
    response = client.post("/send-notification/******@****.***?q=some-query")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Message sent"}
    with open("./log.txt") as f:

	return s, r
}

// A _Sender is used to send values to a Receiver.
type _Sender[Elem any] struct {
	values chan<- Elem
	done   <-chan struct{}
}

// Send sends a value to the receiver. It reports whether the value was sent.
// The value will not be sent if the context is closed or the receiver
// is freed.
func (s *_Sender[Elem]) Send(ctx context.Context, v Elem) bool {
	select {
	case <-ctx.Done():

        background_tasks.add_task(write_log, message)
    return q


@app.post("/send-notification/{email}")
async def send_notification(
    email: str, background_tasks: BackgroundTasks, q: Annotated[str, Depends(get_query)]
):
    message = f"message to {email}\n"
    background_tasks.add_task(write_log, message)

Returning any error will also cancel the stream remotely.

CAREFUL: When utilizing two-way communication, it is important to ensure that the remote handler is not blocked on a send.
If the remote handler is blocked on a send, and the client is trying to send without the remote receiving, 
the operation would become deadlocked if the channels are full.

### Typed handlers

		return errors.New("tls: server sent an unnecessary HelloRetryRequest message")
	}

	if hs.serverHello.cookie != nil {
		hello.cookie = hs.serverHello.cookie
	}

	if hs.serverHello.serverShare.group != 0 {
		c.sendAlert(alertDecodeError)
		return errors.New("tls: received malformed key_share extension")
	}

	// If the server sent a key_share extension selecting a group, ensure it's

 * <li>If the build is started, the daemon may send zero or more {@link OutputMessage} messages.</li>
 * <li>If the build is started, the daemon may send zero or more {@link BuildEvent} messages.</li>
 * <li>If the build is started, the client may send zero or more {@link ForwardInput} messages followed by exactly one {@link CloseInput} message.</li>

    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)

					}
					ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
					// Send the payload.
					t := time.Now()
					st, err := conn.NewStream(ctx, handlerTest, payload)
					if err != nil {
						if debugReqs {
							fmt.Println(err.Error())
						}
						b.Fatal(err.Error())
					}
					got := 0
					sent := 0
					go func() {
						for i := 0; i < messages; i++ {

type TargetStats struct {
	// QueueLength is the queue length if any messages are queued.
	QueueLength int

	// TotalMessages is the total number of messages sent in the lifetime of the target
	TotalMessages int64

	// FailedMessages should log message count that failed to send.
	FailedMessages int64

	// one source is defined.
	Merge(source string, update interface{}) error
}

// mux is a class for merging configuration from multiple sources.  Changes are
// pushed via channels and sent to the merge function.
type mux struct {
	// Invoked when an update is sent to a source.
	merger merger

	// Sources and their lock.
	sourceLock sync.RWMutex
	// Maps source names to channels
	sources map[string]chan interface{}
}