* properties, including:
   *
   * <ul>
   *   <li>{@code java.vendor.version} (added in Java 11, listed as optional as of Java 13)
   *   <li>{@code jdk.module.*} (added in Java 9, optional)
   * </ul>
   */
  public @Nullable String value() {
    return System.getProperty(key);
  }

  /** Returns a string representation of this system property. */

{* ../../docs_src/body_updates/tutorial002_py310.py hl[33] *}

### Rekapitulation zu Teil-Aktualisierungen { #partial-updates-recap }

Zusammengefasst, um Teil-Aktualisierungen vorzunehmen:

* (Optional) verwenden Sie `PATCH` statt `PUT`.
* Lesen Sie die bereits gespeicherten Daten aus.
* Fügen Sie diese in ein Pydantic-Modell ein.
* Erzeugen Sie aus dem empfangenen Modell ein `dict` ohne Defaultwerte (mittels `exclude_unset`).

    }

    @Override
    public Optional<Long> sizeIfKnown() {
      BasicFileAttributes attrs;
      try {
        attrs = readAttributes();
      } catch (IOException e) {
        // Failed to get attributes; we don't know the size.
        return Optional.absent();
      }

      description: |
        Please describe the problem as concisely as possible.
    validations:
      required: true
  - type: textarea
    id: context
    attributes:
      label: Context (optional)
      description: |
        How has this issue affected you? What are you trying to accomplish?
        Providing context helps us come up with a solution that is most useful in the real world
    validations:

import org.codelibs.fess.opensearch.config.exentity.BoostDocumentRule;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.RenderDataUtil;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.response.render.RenderData;

        default:
            break;
        }
        return null;
    }

    /**
     * Creates an HTML response for the list page with optional pre-processing.
     *
     * @param runnable optional runnable to execute before rendering (can be null)
     * @return HTML response for the search request list page
     */
    private HtmlResponse asListHtml(final Runnable runnable) {

import static com.google.common.collect.ImmutableList.toImmutableList;
import static com.google.common.truth.Truth.assertThat;
import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.common.base.Optional;
import com.google.common.collect.ImmutableList;
import com.google.common.io.SourceSinkFactory.ByteSourceFactory;
import com.google.common.io.SourceSinkFactory.CharSourceFactory;
import java.io.BufferedReader;

---> 100%
```

</div>

/// note

When you install with `pip install "fastapi[standard]"` it comes with some default optional standard dependencies, including `fastapi-cloud-cli`, which allows you to deploy to [FastAPI Cloud](https://fastapicloud.com).

If you don't want to have those optional dependencies, you can instead install `pip install fastapi`.

Das Haupt-[Tutorial – Benutzerhandbuch](../tutorial/index.md) sollte ausreichen, um Ihnen einen Überblick über alle Hauptfunktionen von **FastAPI** zu geben.

In den nächsten Abschnitten sehen Sie weitere Optionen, Konfigurationen und zusätzliche Funktionen.

/// tip | Tipp

Die nächsten Abschnitte sind **nicht unbedingt „fortgeschritten“**.

Und es ist möglich, dass für Ihren Anwendungsfall die Lösung in einem davon liegt.

import org.codelibs.fess.opensearch.config.exentity.FileConfig;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.RenderDataUtil;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.response.render.RenderData;