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

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

            @Nonnull

  // nodes.
  // +optional
  optional Scheduling scheduling = 4;
}

// RuntimeClassList is a list of RuntimeClass objects.
message RuntimeClassList {
  // Standard list metadata.
  // More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.ListMeta metadata = 1;

  }

  @Override
  public T get() {
    return reference;
  }

  @Override
  public T or(T defaultValue) {
    checkNotNull(defaultValue, "use Optional.orNull() instead of Optional.or(null)");
    return reference;
  }

  @Override
  public Optional<T> or(Optional<? extends T> secondChoice) {
    checkNotNull(secondChoice);
    return this;
  }

  @Override
  public T or(Supplier<? extends T> supplier) {

  // 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.

  // one status to another
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time lastTransitionTime = 3;

  // reason is the reason for the condition's last transition.
  // +optional
  optional string reason = 4;

  // message is a human-readable explanation containing details about
  // the transition
  // +optional
  optional string message = 5;
}

    @Nonnull
    default Optional<Version> getLowerVersion() {
        return getVersions().isEmpty()
                ? Optional.empty()
                : Optional.of(getVersions().get(0));
    }

    @Nonnull
    default Optional<Version> getHigherVersion() {
        return getVersions().isEmpty()
                ? Optional.empty()
                : Optional.of(getVersions().get(getVersions().size() - 1));
    }

  // nodes.
  // +optional
  optional Scheduling scheduling = 4;
}

// RuntimeClassList is a list of RuntimeClass objects.
message RuntimeClassList {
  // Standard list metadata.
  // More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.ListMeta metadata = 1;

        scheme: str,
        scheme_name: Optional[str] = None,
        description: Optional[str] = None,
        auto_error: bool = True,
    ):
        self.model = HTTPBaseModel(scheme=scheme, description=description)
        self.scheme_name = scheme_name or self.__class__.__name__
        self.auto_error = auto_error

    async def __call__(
        self, request: Request
    ) -> Optional[HTTPAuthorizationCredentials]:

  // +optional
  optional UserSubject user = 2;

  // `group` matches based on user group name.
  // +optional
  optional GroupSubject group = 3;

  // `serviceAccount` matches ServiceAccounts.
  // +optional
  optional ServiceAccountSubject serviceAccount = 4;
}

// UserSubject holds detailed information for user-kind subject.
message UserSubject {

  }

  @AndroidIncompatible
  public void testJavaOptional() {
    FreshValueGenerator generator = new FreshValueGenerator();
    assertEquals(Optional.empty(), generator.generateFresh(new TypeToken<Optional<String>>() {}));
    assertEquals(Optional.of("2"), generator.generateFresh(new TypeToken<Optional<String>>() {}));