```Python hl_lines="1 4"
{!../../docs_src/python_types/tutorial009.py!}
```

O uso de `Optional[str]` em vez de apenas `str` permitirá que o editor o ajude a detectar erros, onde você pode estar assumindo que um valor é sempre um `str`, quando na verdade também pode ser `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(
                """

  // APIGroups, APIVersions, Resources, etc.
  optional Rule rule = 2;
}

// ServiceReference holds a reference to Service.legacy.k8s.io
message ServiceReference {
  // `namespace` is the namespace of the service.
  // Required
  optional string namespace = 1;

  // `name` is the name of the service.
  // Required
  optional string name = 2;

  // `path` is an optional URL path which will be sent in any request to

            pomPath = context.locate(pomPath);
        }

        if (pomPath == null || !Files.isRegularFile(pomPath)) {
            return Optional.empty();
        }

        Optional<RelativeProject> mappedProject = Optional.ofNullable(context.getRawModel(pomFile, pomPath.normalize()))
                .map(BuildModelSourceTransformer::toRelativeProject);

        if (mappedProject.isPresent()) {

  //
  // Defaults to "Equivalent"
  // +optional
  optional string matchPolicy = 7;
}

// NamedRuleWithOperations is a tuple of Operations and Resources with ResourceNames.
// +structType=atomic
message NamedRuleWithOperations {
  // ResourceNames is an optional white list of names that the rule applies to.  An empty set means that everything is allowed.
  // +listType=atomic
  // +optional
  repeated string resourceNames = 1;

@REM
@REM   JAVA_HOME           (Optional) Points to a Java installation.
@REM   MAVEN_BATCH_ECHO    (Optional) Set to 'on' to enable the echoing of the batch commands.
@REM   MAVEN_BATCH_PAUSE   (Optional) set to 'on' to wait for a key stroke before ending.
@REM   MAVEN_OPTS          (Optional) Java runtime options used when Maven is executed.
@REM   MAVEN_SKIP_RC       (Optional) Flag to disable loading of mavenrc files.

			Optional:    true,
			Type:        "path",
			Sensitive:   true,
		},
		config.HelpKV{
			Key:         ClientCertKey,
			Description: `client cert key for mTLS authentication` + defaultHelpPostfix(ClientCertKey),
			Optional:    true,
			Type:        "path",
			Sensitive:   true,
		},
		config.HelpKV{
			Key:         config.Comment,
			Description: config.DefaultComment,
			Optional:    true,

            @Nonnull
            @Override
            public Optional<Source> getInstallationToolchainsSource() {
                return Optional.ofNullable(installationToolchainsSource);
            }

            @Nonnull
            @Override
            public Optional<Source> getUserToolchainsSource() {
                return Optional.ofNullable(userToolchainsSource);
            }
        }
    }

   * @throws NullPointerException if any element in the stream is {@code null}.
   * @return {@code Optional.of(onlyElement)} if the stream has exactly one element (must not be
   *     {@code null}) and returns {@code Optional.empty()} if it has none.
   */
  @SuppressWarnings("unchecked")
  public static <T> Collector<T, ?, Optional<T>> toOptional() {
    return (Collector) TO_OPTIONAL;
  }

  // the smallest value of such global default PriorityClasses will be used as the default priority.
  // +optional
  optional bool globalDefault = 3;

  // description is an arbitrary string that usually provides guidelines on
  // when this priority class should be used.
  // +optional
  optional string description = 4;

  // preemptionPolicy is the Policy for preempting pods with lower priority.