public class MappedCollection<U, V> extends AbstractCollection<U> {
    private final Collection<V> list;
    private final Function<V, U> mapper;

    public MappedCollection(Collection<V> list, Function<V, U> mapper) {
        this.list = list;
        this.mapper = mapper;
    }

    @Override
    public Iterator<U> iterator() {
        Iterator<V> it = list.iterator();
        return new Iterator<U>() {

							<mapper>
								<type>perm</type>
								<user>${packaging.fess.user}</user>
								<group>${packaging.fess.group}</group>
							</mapper>
						</data>
						<data>
							<type>directory</type>
							<src>${project.build.directory}/fess/WEB-INF/classes/org/codelibs/fess/tomcat</src>
							<mapper>
								<type>perm</type>

public class MappedList<U, V> extends AbstractList<U> {
    private final List<V> list;
    private final Function<V, U> mapper;

    public MappedList(List<V> list, Function<V, U> mapper) {
        this.list = list;
        this.mapper = mapper;
    }

    @Override
    public U get(int index) {
        return mapper.apply(list.get(index));
    }

    @Override
    public int size() {
        return list.size();
    }

public class MappedCollection<U, V> extends AbstractCollection<U> {
    private final Collection<V> list;
    private final Function<V, U> mapper;

    public MappedCollection(Collection<V> list, Function<V, U> mapper) {
        this.list = list;
        this.mapper = mapper;
    }

    @Override
    public Iterator<U> iterator() {
        Iterator<V> it = list.iterator();
        return new Iterator<U>() {

public class MappedList<U, V> extends AbstractList<U> {
    private final List<V> list;
    private final Function<V, U> mapper;

    public MappedList(List<V> list, Function<V, U> mapper) {
        this.list = list;
        this.mapper = mapper;
    }

    @Override
    public U get(int index) {
        return mapper.apply(list.get(index));
    }

    @Override
    public int size() {
        return list.size();
    }

			<param name="module.zip.version" value="${opensearch.version}" />
		</antcall>
		<!-- mapper-extras -->
		<antcall target="install.module">
			<param name="repo.url" value="${maven.release.repo.url}" />
			<param name="module.groupId" value="org/codelibs/opensearch/module" />
			<param name="module.name.prefix" value="" />
			<param name="module.name" value="mapper-extras" />
			<param name="module.version" value="${opensearch.version}" />

        }
        return clazz.cast(o);
    }

    static <U, V> List<V> map(Collection<U> list, Function<U, V> mapper) {
        return list.stream().map(mapper).collect(Collectors.toList());
    }

  - Settings, set `Valid Redirect URIs` to `*`, expand `Advanced Settings` and set `Access Token Lifespan` to `1 Hours`
  - Save

- Go to Clients
  - Click on `account`
  - Mappers
  - Create
    - `Name` with any text
    - `Mapper Type` is `User Attribute`
    - `User Attribute` is `policy`
    - `Token Claim Name` is `policy`
    - `Claim JSON Type` is `string`
  - Save

                return plugin;
            }
        });
    }

    static <T> List<T> map(List<T> list, Function<T, T> mapper) {
        List<T> newList = list;
        for (int i = 0; i < newList.size(); i++) {
            T oldT = newList.get(i);
            T newT = mapper.apply(oldT);
            if (newT != oldT) {
                if (newList == list) {
                    newList = new ArrayList<>(list);

        }
        return clazz.cast(o);
    }

    static <U, V> List<V> map(Collection<U> list, Function<U, V> mapper) {
        return list.stream().map(mapper).collect(Collectors.toList());
    }