Indem Sie von `str` erben, weiß die API Dokumentation, dass die Werte des Enums vom Typ `str` sein müssen, und wird in der Lage sein, korrekt zu rendern.

Erstellen Sie dann Klassen-Attribute mit festgelegten Werten, welches die erlaubten Werte sein werden:

{* ../../docs_src/path_params/tutorial005.py hl[1,6:9] *}

/// info

import org.codelibs.fess.mylasta.mail.EsStatusPostcard;
import org.codelibs.fess.opensearch.client.SearchEngineClient;
import org.codelibs.fess.util.ComponentUtil;
import org.dbflute.mail.send.hook.SMailCallbackContext;
import org.lastaflute.core.mail.Postbox;

/**
 * Job for pinging search engine.
 */
public class PingSearchEngineJob {

    /**
     * Default constructor.
     */

	return s.newCache, nil
}

// sendUpdate() should be called on a regular basis when the newCache contains more recent total than previously.
// May or may not send an update upstream.
func (f *folderScanner) sendUpdate() {
	// Send at most an update every minute.
	if f.updates == nil || time.Since(f.lastUpdate) < time.Minute {
		return
	}
	if flat := f.updateCache.sizeRecursive(f.newCache.Info.Name); flat != nil {

errors.cannot_delete_doc_because_of_running = A crawler is running. You cannot delete documents.
errors.failed_to_delete_doc_in_admin = Failed to delete a document.
errors.failed_to_send_testmail=Failed to send a test mail.
errors.invalid_query_unknown = The specified query has an unknown condition.
errors.invalid_query_parse_error = The given query is invalid.
errors.invalid_query_sort_value = The specified sort {0} is invalid.

errors.cannot_delete_doc_because_of_running = A crawler is running. You cannot delete documents.
errors.failed_to_delete_doc_in_admin = Failed to delete a document.
errors.failed_to_send_testmail=Failed to send a test mail.
errors.invalid_query_unknown = The specified query has an unknown condition.
errors.invalid_query_parse_error = The given query is invalid.
errors.invalid_query_sort_value = The specified sort {0} is invalid.

        if (spToken instanceof final NegTokenTarg targ) {
            if (targ.getResult() == NegTokenTarg.ACCEPT_COMPLETED && this.mechContext.isEstablished()) {
                // server sent final token
                verifyMechListMIC(targ.getMechanismListMIC());
                if (!this.disableMic || this.requireMic) {
                    mechMIC = calculateMechListMIC();
                }

Diese Felder werden also in der JSON-Response enthalten sein.

/// tip | Tipp

Beachten Sie, dass Defaultwerte alles Mögliche sein können, nicht nur `None`.

Sie können eine Liste (`[]`), ein `float` `10.5`, usw. sein.

///

### `response_model_include` und `response_model_exclude`

# WebSockets

When defining WebSockets, you normally declare a parameter of type `WebSocket` and with it you can read data from the client and send data to it.

It is provided directly by Starlette, but you can import it from `fastapi`:

```python
from fastapi import WebSocket
```

/// tip

   *
   * @param request the request sent over the network. It is an error to access the body of this
   *     request.
   */
  open fun requestHeadersEnd(
    call: Call,
    request: Request,
  ) {
  }

  /**
   * Invoked just prior to sending a request body.  Will only be invoked for request allowing and
   * having a request body to send.
   *

## Dokumentation des Callbacks

Der tatsächliche Callback-Code hängt stark von Ihrer eigenen API-Anwendung ab.

Und er wird wahrscheinlich von Anwendung zu Anwendung sehr unterschiedlich sein.

Es könnten nur eine oder zwei Codezeilen sein, wie zum Beispiel:

```Python
callback_url = "https://example.com/api/v1/invoices/events/"
httpx.post(callback_url, json={"description": "Invoice paid", "paid": True})
```