* @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
abstract class AbstractUndirectedNetworkConnections<N, E> implements NetworkConnections<N, E> {
  /** Keys are edges incident to the origin node, values are the node at the other end. */
  final Map<E, N> incidentEdgeMap;

  AbstractUndirectedNetworkConnections(Map<E, N> incidentEdgeMap) {
    this.incidentEdgeMap = checkNotNull(incidentEdgeMap);
  }

{* ../../docs_src/middleware/tutorial001.py hl[10,12:13] *}

## 🎏 🛠️

👆 💪 ⏪ ✍ 🌖 🔃 🎏 🛠️ [🏧 👩‍💻 🦮: 🏧 🛠️](../advanced/middleware.md){.internal-link target=_blank}.

- [ ] Make sure that all commits are [signed off](https://git-scm.com/docs/git-commit#Documentation/git-commit.txt---signoff) to indicate that you agree to the terms of [Developer Certificate of Origin](https://developercertificate.org/).

api.dashboard.response.headers=Referrer-Policy:strict-origin-when-cross-origin
# Allowed origins for CORS.
api.cors.allow.origin=*
# Allowed HTTP methods for CORS.
api.cors.allow.methods=GET, POST, OPTIONS, DELETE, PUT
# Max age for CORS preflight requests.
api.cors.max.age=3600
# Allowed headers for CORS.
api.cors.allow.headers=Origin, Content-Type, Accept, Authorization, X-Requested-With

می‌توانید بعداً در مورد میان‌افزارهای دیگر در [راهنمای کاربر پیشرفته: میان‌افزار پیشرفته](../advanced/middleware.md){.internal-link target=_blank} بیشتر بخوانید.

شما در بخش بعدی در مورد این که چگونه با استفاده از یک میان‌افزار، <abbr title="Cross-Origin Resource Sharing">CORS</abbr> را مدیریت کنید، خواهید خواند....

        final String clusterName = UUID.randomUUID().toString();
        runner.onBuild((number, settingsBuilder) -> {
            settingsBuilder.put("http.cors.enabled", true);
            settingsBuilder.put("http.cors.allow-origin", "*");
            settingsBuilder.put("discovery.type", "single-node");
        }).build(newConfigs().clusterName(clusterName).numOfNode(1));

        // wait for yellow status
        runner.ensureYellow();

* Grundlegende Startmodelle für Benutzer (ändern und entfernen Sie nach Bedarf).
* **Alembic**-Migrationen.
* **CORS** (Cross Origin Resource Sharing).
* **Celery**-Worker, welche Modelle und Code aus dem Rest des Backends selektiv importieren und verwenden können.

hinzugefügt werden können.

Wenn Sie jedoch benutzerdefinierte Header haben, die ein Client in einem Browser sehen können soll, müssen Sie diese zu Ihren CORS-Konfigurationen hinzufügen (weitere Informationen finden Sie unter [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), unter Verwendung des Parameters `expose_headers`, dokumentiert in <a href="https://www.starlette.io/middleware/#corsmiddleware" class="external-link" target="_blank">Starlettes...

P/Headers" class="external-link" target="_blank">using the 'X-' prefix</a>.

But if you have custom headers that you want a client in a browser to be able to see, you need to add them to your CORS configurations (read more in [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), using the parameter `expose_headers` documented in <a href="https://www.starlette.io/middleware/#corsmiddleware" class="external-link" target="_blank">Starlette's CORS docs</a>....

     * information that is available at the point the problem occurs and as such merely serves as best effort
     * to provide information to the user to track the problem back to its origin.
     *
     * @return The identifier of the model from which the problem originated or an empty string if unknown, never
     *         {@code null}.
     */
    @Nonnull
    String getModelId();

    /**