///

```Python hl_lines="10"
{!> ../../docs_src/request_form_models/tutorial002.py!}
```

////

If a client tries to send some extra data, they will receive an **error** response.

For example, if the client tries to send the form fields:

* `username`: `Rick`
* `password`: `Portal Gun`
* `extra`: `Mr. Poopybutthole`

	err := target.checkAndInitClient(ctx)
	if err != nil {
		return err
	}

	err = target.send(eventData)
	if xnet.IsNetworkOrHostDown(err, false) {
		return store.ErrNotConnected
	}
	return err
}

// send - sends the event to the target.
func (target *ElasticsearchTarget) send(eventData event.Event) error {
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

			Optional:    true,
			Type:        "string",
			Sensitive:   true,
		},
		config.HelpKV{
			Key:         BatchSize,
			Description: "Number of events per HTTP send to webhook target",
			Optional:    true,
			Type:        "number",
		},
		config.HelpKV{
			Key:         QueueSize,
			Description: "configure channel queue size for webhook targets",
			Optional:    true,

    final LoadingCache<String, String> cache =
        CacheBuilder.newBuilder()
            .concurrencyLevel(1)
            .removalListener(listener)
            .build(computingFunction);

    // seed the map, so its segment's count > 0
    cache.getUnchecked("a");
    shouldWait.set(true);

    final CountDownLatch computationStarted = new CountDownLatch(1);

                    Smb2SetInfoRequest treq = new Smb2SetInfoRequest(th.getConfig(), fh.getFileId());
                    treq.setFileInformation(new FileEndOfFileInformation(0));
                    th.send(treq, RequestParam.NO_RETRY);
                }
            }
        }
        catch ( CIFSException e ) {
            throw SmbException.wrap(e);
        }
    }

            try ( SmbTreeHandleInternal th = (SmbTreeHandleInternal) f.getTreeHandle();
                  SmbSessionInternal sess = th.getSession().unwrap(SmbSessionInternal.class);
                  SmbTransportInternal t = (SmbTransportInternal) sess.getTransport() ) {

                int before = t.getInflightRequests();
                if ( before > 0 ) {

The user of your API (an external developer) will create an invoice in your API with a POST request.

Then your API will (let's imagine):

* Send the invoice to some customer of the external developer.
* Collect the money.
* Send a notification back to the API user (the external developer).

		if err := ch.Confirm(false); err != nil {
			ch.Close()
			return nil, nil, err
		}
		return ch, confirms, nil
	}

	return ch, nil, nil
}

// send - sends an event to the AMQP091.
func (target *AMQPTarget) send(eventData event.Event, ch *amqp091.Channel, confirms chan amqp091.Confirmation) error {
	objectName, err := url.QueryUnescape(eventData.S3.Object.Key)
	if err != nil {
		return err
	}

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

  }

  @VisibleForTesting
  static long murmurHash64WithSeed(byte[] bytes, int offset, int length, long seed) {
    long mul = K3;
    int topBit = 0x7;

    int lengthAligned = length & ~topBit;
    int lengthRemainder = length & topBit;
    long hash = seed ^ (length * mul);

    for (int i = 0; i < lengthAligned; i += 8) {
      long loaded = load64(bytes, offset + i);