</dependency>
    <dependency>
      <groupId>maven-test</groupId>
      <artifactId>t05-d</artifactId>
      <version>1.1</version>
      <type>jar</type>
      <scope>compile</scope>
      <optional>false</optional>
    </dependency>
  </dependencies>

  /** Puts all the associations from {@code rangeMap} into this range map (optional operation). */
  void putAll(RangeMap<K, ? extends V> rangeMap);

  /** Removes all associations from this range map (optional operation). */
  void clear();

  /**
   * Removes all associations from this range map in the specified range (optional operation).
   *

  <dependencies>
    <dependency>
      <groupId>maven-test</groupId>
      <artifactId>t06-d</artifactId>
      <version>1.1</version>
      <type>jar</type>
      <scope>compile</scope>
      <optional>true</optional>
    </dependency>
  </dependencies>

from typing import Optional

from fastapi import APIRouter, FastAPI, File, UploadFile
from fastapi.exceptions import HTTPException
from fastapi.testclient import TestClient

app = FastAPI()

router = APIRouter()


class ContentSizeLimitMiddleware:
    """Content size limiting middleware for ASGI applications
    Args:
      app (ASGI application): ASGI application

    }

    @Override
    public Optional<Long> lengthIfKnown() {
      long result = 0L;
      for (CharSource source : sources) {
        Optional<Long> lengthIfKnown = source.lengthIfKnown();
        if (!lengthIfKnown.isPresent()) {
          return Optional.absent();
        }
        result += lengthIfKnown.get();
      }
      return Optional.of(result);
    }

    @Override

     * @see org.apache.maven.api.services.ArtifactManager#getPath(Artifact)
     */
    @Nonnull
    default Optional<ProducedArtifact> getMainArtifact() {
        List<ProducedArtifact> artifacts = getArtifacts();
        return artifacts.size() == 2 ? Optional.of(artifacts.get(1)) : Optional.empty();
    }

    /**

http://127.0.0.1:8000/items/?skip=20
```

The parameter values in your function will be:

* `skip=20`: because you set it in the URL
* `limit=10`: because that was the default value

## Optional parameters

The same way, you can declare optional query parameters, by setting their default to `None`:

//// tab | Python 3.10+

```Python hl_lines="7"
{!> ../../docs_src/query_params/tutorial002_py310.py!}
```

////

        if (lifecycleMapping == null) {
            return Optional.empty();
        }
        Type type = typeRegistry.lookup(id).orElse(null);
        if (type == null) {
            return Optional.empty();
        }
        return Optional.of(new DefaultPackaging(id, type, getPlugins(lifecycleMapping)));
    }

* Datenvalidierung
* Automatische Dokumentation

## Defaultwerte

Da Query-Parameter nicht ein festgelegter Teil des Pfades sind, können sie optional sein und Defaultwerte haben.

Im obigen Beispiel haben sie die Defaultwerte `skip=0` und `limit=10`.

Wenn Sie also zur URL:

```
http://127.0.0.1:8000/items/
```

    </dependency>
    <dependency>
      <groupId>maven-test</groupId>
      <artifactId>t06-d</artifactId>
      <version>1.1</version>
      <type>jar</type>
      <scope>compile</scope>
      <optional>false</optional>
    </dependency>
  </dependencies>