Function object

Returns FieldDef & {
    default(
        value: InferItem<S> | (() => T),
    ): FieldApi<InferItem<S>, false, true>;
    immutable(): FieldApi<InferItem<S>, false, false>;
    optional(): FieldApi<InferItem<S>, false, false>;
    required(): FieldApi<InferItem<S>, true, false>;
    version(): FieldApi<InferItem<S>, false, false>;
} & { _objectShape: S }