* Optional<Number>} (where {@code Number} is the desired output type) solves the problem:
   *
   * {@snippet :
   * Optional<Number> optionalInt = (Optional) getSomeOptionalInt();
   * Number value = optionalInt.or(0.5); // fine
   *
   * FluentIterable<? extends Number> numbers = getSomeNumbers();
   * Optional<Number> first = (Optional) numbers.first();

    List<Optional<Object>> optionals = ImmutableList.of(Optional.absent(), Optional.absent());
    assertThat(Optional.presentInstances(optionals)).isEmpty();
  }

  public void testPresentInstances_somePresent() {
    List<Optional<String>> optionals =
        ImmutableList.of(Optional.of("a"), Optional.<String>absent(), Optional.of("c"));

* `limit=10`: weil das der Defaultwert ist

## Optionale Parameter { #optional-parameters }

Auf die gleiche Weise können Sie optionale Query-Parameter deklarieren, indem Sie deren Defaultwert auf `None` setzen:

{* ../../docs_src/query_params/tutorial002_py310.py hl[7] *}

In diesem Fall wird der Funktionsparameter `q` optional und standardmäßig `None` sein.

/// check | Testen

   */
  private Iterable<List<Object>> buildCartesianProduct(Set<?>... sets) {
    List<Set<Optional<?>>> optionalSets = Lists.newArrayListWithExpectedSize(sets.length);
    for (Set<?> set : sets) {
      Set<Optional<?>> optionalSet =
          Sets.newLinkedHashSet(Iterables.transform(set, NULLABLE_TO_OPTIONAL));
      optionalSets.add(optionalSet);
    }

      } else if (value instanceof Map) {
        return ((Map<?, ?>) value).isEmpty();
      } else if (value instanceof java.util.Optional) {
        return !((java.util.Optional<?>) value).isPresent();
      } else if (value instanceof OptionalInt) {
        return !((OptionalInt) value).isPresent();
      } else if (value instanceof OptionalLong) {
        return !((OptionalLong) value).isPresent();

```

////

#### `Union` oder `Optional` verwenden? { #using-union-or-optional }

Wenn Sie eine Python-Version unterhalb 3.10 verwenden, hier ist mein sehr **subjektiver** Standpunkt dazu:

* 🚨 Vermeiden Sie `Optional[SomeType]`
* Stattdessen ✨ **verwenden Sie `Union[SomeType, None]`** ✨.

#    credentials:
#      accessKey: minioadmin # Required
#      secretKey: minioadmin # Required
#    # sessionToken: SESSION-TOKEN # Optional only available when rotating credentials are used
    snowball: # automatically activated if the source is local
      disable: true # optionally turn-off snowball archive transfer
#      batch: 100 # upto this many objects per archive

   *
   * <p><b>Java 9 users:</b> use {@code optional.stream()} instead.
   */
  @Beta
  @InlineMe(replacement = "optional.stream()")
  @InlineMeValidationDisabled("Java 9+ API only")
  public static IntStream stream(OptionalInt optional) {
    return optional.isPresent() ? IntStream.of(optional.getAsInt()) : IntStream.empty();
  }

  /**
   * If a value is present in {@code optional}, returns a stream containing only that element,

			Optional:    true,
		},
		HelpKV{
			Key:         Comment,
			Type:        "sentence",
			Description: DefaultComment,
			Optional:    true,
		},
	}

	RegionHelp = HelpKVS{
		HelpKV{
			Key:         RegionName,
			Type:        "string",
			Description: `[DEPRECATED] name of the location of the server e.g. "us-west-rack2"`,
			Optional:    true,
		},
		HelpKV{

   *
   * <p><b>Java 9 users:</b> use {@code optional.stream()} instead.
   */
  @Beta
  @InlineMe(replacement = "optional.stream()")
  @InlineMeValidationDisabled("Java 9+ API only")
  public static IntStream stream(OptionalInt optional) {
    return optional.isPresent() ? IntStream.of(optional.getAsInt()) : IntStream.empty();
  }

  /**
   * If a value is present in {@code optional}, returns a stream containing only that element,