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

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

   * Point ::= SEQUENCE {
   *   x [0] INTEGER OPTIONAL,
   *   y [1] INTEGER OPTIONAL
   * }
   * ```
   *
   * You may also specify a tag class like [DerHeader.TAG_CLASS_APPLICATION]. The default tag class
   * is [DerHeader.TAG_CLASS_CONTEXT_SPECIFIC].
   *
   * ```
   * Point ::= SEQUENCE {
   *   x [APPLICATION 0] INTEGER OPTIONAL,
   *   y [APPLICATION 1] INTEGER OPTIONAL
   * }
   * ```
   */
  fun withTag(

			Description: `name for the site e.g. "cal-rack0"`,
			Optional:    true,
		},
		HelpKV{
			Key:         RegionKey,
			Type:        "string",
			Description: `name of the location of the server e.g. "us-west-1"`,
			Optional:    true,
		},
		HelpKV{
			Key:         Comment,
			Type:        "sentence",
			Description: DefaultComment,
			Optional:    true,
		},
	}

	RegionHelp = HelpKVS{
		HelpKV{

```

////

#### Using `Union` or `Optional` { #using-union-or-optional }

If you are using a Python version below 3.10, here's a tip from my very **subjective** point of view:

* 🚨 Avoid using `Optional[SomeType]`
* Instead ✨ **use `Union[SomeType, None]`** ✨.

            ),
        ],
        scheme_name: Annotated[
            Optional[str],
            Doc(
                """
                Security scheme name.

                It will be included in the generated OpenAPI (e.g. visible at `/docs`).
                """
            ),
        ] = None,
        description: Annotated[
            Optional[str],
            Doc(
                """

			Key:         apiRequestsMax,
			Description: `set the maximum number of concurrent requests (default: auto)`,
			Optional:    true,
			Type:        "number",
		},
		config.HelpKV{
			Key:         apiClusterDeadline,
			Description: `set the deadline for cluster readiness check` + defaultHelpPostfix(apiClusterDeadline),
			Optional:    true,
			Type:        "duration",
		},
		config.HelpKV{
			Key:         apiCorsAllowOrigin,

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

## Optional parameters { #optional-parameters }

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

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

In this case, the function parameter `q` will be optional, and will be `None` by default.

/// check

            .addValue(Collections.emptyMap())
            .addValue(null)
            .add(SHORT_NAME, Optional.of("1"))
            .add(LONG_NAME, Optional.of("1"))
            .add(SHORT_NAME, Optional.absent())
            .add(LONG_NAME, Optional.absent())
            .add(SHORT_NAME, Optional.of("2"))
            .add(SHORT_NAME, Optional.absent())
            .addValue(null)
            .add(SHORT_NAME, new int[] {1})

        }

        @Named
        @Singleton
        static class TestModelParser implements ModelParser {
            @Override
            public Optional<Source> locate(Path dir) {
                return Optional.empty();
            }

            @Override
            public Model parse(Source source, Map<String, ?> options) throws ModelParserException {
                return null;

package org.apache.maven.cling.invoker.cisupport;

import java.util.Optional;

import org.apache.maven.api.cli.cisupport.CIInfo;

/**
 * Circle CI support.
 */
public class CircleCIDetector implements CIDetector {
    public static final String NAME = "CircleCI";

    private static final String CIRCLECI = "CIRCLECI";

    @Override
    public Optional<CIInfo> detectCI() {
        String ciEnv = System.getenv(CIRCLECI);