.put(Charset.class, UTF_8)
          .put(Currency.class, Currency.getInstance(Locale.US))
          .put(Locale.class, Locale.US)
          .put(Optional.class, Optional.empty())
          .put(OptionalInt.class, OptionalInt.empty())
          .put(OptionalLong.class, OptionalLong.empty())
          .put(OptionalDouble.class, OptionalDouble.empty())
          .put(UUID.class, UUID.randomUUID())

     * @param active Should the project be activated?
     * @param optional Can the build continue if the project does not exist?
     */
    public void addProjectActivation(String selector, boolean active, boolean optional) {
        final ActivationSettings settings = ActivationSettings.of(active, optional);
        this.activations.add(new ProjectActivationSettings(selector, settings));
    }

    assertEquals(0, ArbitraryInstances.get(Number.class));
    assertEquals(UTF_8, ArbitraryInstances.get(Charset.class));
    assertEquals(Optional.empty(), ArbitraryInstances.get(Optional.class));
    assertEquals(OptionalInt.empty(), ArbitraryInstances.get(OptionalInt.class));
    assertEquals(OptionalLong.empty(), ArbitraryInstances.get(OptionalLong.class));

  }

  @Empty
  <T> Optional<T> generateJavaOptional() {
    return Optional.empty();
  }

  @Generates
  <T> Optional<T> generateJavaOptional(T value) {
    return Optional.of(value);
  }

  @Generates
  OptionalInt generateOptionalInt() {
    return OptionalInt.of(generateInt());
  }

  @Generates
  OptionalLong generateOptionalLong() {

Notice that the input model is still validated.

So, if you want to receive partial updates that can omit all the attributes, you need to have a model with all the attributes marked as optional (with default values or `None`).

To distinguish from the models with all optional values for **updates** and models with required values for **creation**, you can use the ideas described in [Extra Models](extra-models.md){.internal-link target=_blank}.

   * Predicates.notNull())}, static importing as necessary.
   *
   * <p><b>Note:</b> if {@code first} is represented as an {@link Optional}, this can be
   * accomplished with {@link Optional#or(Object) first.or(second)}. That approach also allows for
   * lazy evaluation of the fallback instance, using {@link Optional#or(Supplier)
   * first.or(supplier)}.
   *
   * <p><b>Java 9 users:</b> use {@code java.util.Objects.requireNonNullElse(first, second)}

Das ist keine Limitation von **FastAPI**, sondern Teil des HTTP-Protokolls.

///

## Optionaler Datei-Upload { #optional-file-upload }

Sie können eine Datei optional machen, indem Sie Standard-Typannotationen verwenden und den Defaultwert auf `None` setzen:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

```

////

#### Uso de `Union` u `Optional` { #using-union-or-optional }

Si estás usando una versión de Python inferior a 3.10, aquí tienes un consejo desde mi punto de vista muy **subjetivo**:

* 🚨 Evita usar `Optional[SomeType]`
* En su lugar ✨ **usa `Union[SomeType, None]`** ✨.

{* ../../docs_src/body_nested_models/tutorial007_py310.py hl[7,12,18,21,25] *}

/// info | Info

Beachten Sie, wie `Offer` eine Liste von `Item`s hat, die ihrerseits eine optionale Liste von `Image`s haben.

///

## Bodys aus reinen Listen { #bodies-of-pure-lists }

import org.apache.logging.log4j.Logger;

/**
 * A thread that reads from an input stream line by line and maintains a buffer of recent lines.
 * This class provides functionality to read input stream data asynchronously,
 * optionally process each line with a callback function, and maintain a circular buffer
 * of recent lines for retrieval.
 */
public class InputStreamThread extends Thread {
    /** Logger instance for this class */