return Optional.of(Boolean.TRUE);
        }
        return Optional.empty();
    }

    @Override
    @Nonnull
    public Optional<Boolean> model() {
        if (commandLine.hasOption(CLIManager.MODEL)) {
            return Optional.of(Boolean.TRUE);
        }
        return Optional.empty();
    }

    @Override
    @Nonnull
    public Optional<Boolean> plugins() {

            return Optional.of(Boolean.TRUE);
        }
        return Optional.empty();
    }

    @Override
    public Optional<Boolean> showVersion() {
        if (commandLine.hasOption(CLIManager.SHOW_VERSION)) {
            return Optional.of(Boolean.TRUE);
        }
        return Optional.empty();
    }

    @Override
    public Optional<Boolean> quiet() {

    public <T> T lookup(Class<T> type, String name) {
        return null;
    }

    @Override
    public <T> Optional<T> lookupOptional(Class<T> type) {
        return Optional.empty();
    }

    @Override
    public <T> Optional<T> lookupOptional(Class<T> type, String name) {
        return Optional.empty();
    }

    @Override
    public <T> List<T> lookupList(Class<T> type) {
        return List.of();
    }

* `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

    ] = None,
    title: Annotated[
        Optional[str],
        Doc(
            """
            Human-readable title.
            """
        ),
    ] = None,
    description: Annotated[
        Optional[str],
        Doc(
            """
            Human-readable description.
            """
        ),
    ] = None,
    gt: Annotated[
        Optional[float],
        Doc(
            """

     *
     * @return an {@link Optional} containing the list of goals, or empty if not specified
     */
    @Nonnull
    Optional<List<String>> goals();

    /**
     * Returns the target POM model version for upgrades.
     * Supported values include "4.0.0" and "4.1.0".
     *
     * @return an {@link Optional} containing the model version, or empty if not specified
     */
    @Nonnull

        // v1 == 0.
        .optional(defaultValue = 0),
      Adapters.INTEGER_AS_BIG_INTEGER,
      algorithmIdentifier,
      name,
      validity,
      name,
      subjectPublicKeyInfo,
      Adapters.BIT_STRING.withTag(tag = 1L).optional(),
      Adapters.BIT_STRING.withTag(tag = 2L).optional(),
      extension.asSequenceOf().withExplicitBox(tag = 3).optional(defaultValue = listOf()),
      decompose = {

 * under the License.
 */
package org.apache.maven.graph;

import java.io.File;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import java.util.stream.Collectors;

import org.apache.maven.MavenExecutionException;
import org.apache.maven.execution.MavenExecutionRequest;
import org.apache.maven.execution.ProjectActivation;

            throw new LookupException(e);
        }
    }

    @Override
    public <T> Optional<T> lookupOptional(Class<T> type) {
        try {
            return Optional.of(container.lookup(type));
        } catch (ComponentLookupException e) {
            if (e.getCause() instanceof NoSuchElementException) {
                return Optional.empty();
            }
            throw new LookupException(e);
        }
    }

     */
    @Nonnull
    Optional<Path> rootDirectory();

    /**
     * Returns the input stream for the Maven execution, if running in embedded mode.
     *
     * @return an {@link Optional} containing the input stream, or empty if not applicable
     */
    @Nonnull
    default Optional<InputStream> stdIn() {
        return Optional.ofNullable(parserRequest().stdIn());
    }

    /**