* invokeAll}, and {@code invokeAny} methods, so any special handling of tasks must be implemented
   * in the delegate's {@code execute} method or by wrapping the returned {@code
   * ListeningExecutorService}.
   *
   * <p>If the delegate executor was already an instance of {@code ListeningExecutorService}, it is

    }

    // groupId -> (artifactId -> (version -> project)))
    private Map<String, Map<String, Map<String, MavenProject>>> getAllProjects() {
        // compute the projects mapping
        if (allProjects == null) {
            List<MavenProject> allProjects = session.getAllProjects();
            if (allProjects != null) {

   * first permutation will be in ascending order, and the last will be in descending order.
   *
   * <p>Elements that compare equal are considered equal and no new permutations are created by
   * swapping them.
   *
   * <p>An empty iterable has only one permutation, which is an empty list.
   *
   * @param elements the original iterable whose elements have to be permuted.

  /**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableBiMap} whose keys
   * and values are the result of applying the provided mapping functions to the input elements.
   * Entries appear in the result {@code ImmutableBiMap} in encounter order.
   *
   * <p>If the mapped keys or values contain duplicates (according to {@link

                "fess_config.file_config", //
                "fess_config.job_log", //
                "fess_config.key_match", //
                "fess_config.label_type", //
                "fess_config.path_mapping", //
                "fess_config.related_content", //
                "fess_config.related_query", //
                "fess_config.request_header", //
                "fess_config.role_type", //

    implements SetMultimap<K, V> {
  /**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableSetMultimap}
   * whose keys and values are the result of applying the provided mapping functions to the input
   * elements.
   *
   * <p>For streams with defined encounter order (as defined in the Ordering section of the {@link
   * java.util.stream} Javadoc), that order is preserved, but entries are <a

   */
  @SuppressWarnings("unchecked")
  public static <K extends Comparable<?>, V> ImmutableRangeMap<K, V> of() {
    return (ImmutableRangeMap<K, V>) EMPTY;
  }

  /** Returns an immutable range map mapping a single range to a single value. */
  public static <K extends Comparable<?>, V> ImmutableRangeMap<K, V> of(Range<K> range, V value) {
    return new ImmutableRangeMap<>(ImmutableList.of(range), ImmutableList.of(value));
  }

   * first permutation will be in ascending order, and the last will be in descending order.
   *
   * <p>Elements that compare equal are considered equal and no new permutations are created by
   * swapping them.
   *
   * <p>An empty iterable has only one permutation, which is an empty list.
   *
   * @param elements the original iterable whose elements have to be permuted.

   */
  @SuppressWarnings("unchecked")
  public static <K extends Comparable<?>, V> ImmutableRangeMap<K, V> of() {
    return (ImmutableRangeMap<K, V>) EMPTY;
  }

  /** Returns an immutable range map mapping a single range to a single value. */
  public static <K extends Comparable<?>, V> ImmutableRangeMap<K, V> of(Range<K> range, V value) {
    return new ImmutableRangeMap<>(ImmutableList.of(range), ImmutableList.of(value));
  }

  /**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableMap} whose keys
   * and values are the result of applying the provided mapping functions to the input elements.
   * Entries appear in the result {@code ImmutableMap} in encounter order.
   *
   * <p>If the mapped keys contain duplicates (according to {@link Object#equals(Object)}, an {@code