final LdapManager ldapManager = ComponentUtil.getLdapManager();
                permissions = distinct(ArrayUtils.addAll(ldapManager.getRoles(this, baseDn, accountFilter, groupFilter, roles -> {
                    permissions = distinct(roles);
                    ComponentUtil.getActivityHelper().permissionChanged(OptionalThing.of(new FessUserBean(this)));

                    Arrays.spliterator(new String[] {"abc", "", "de", "f", "g", ""}),
                    (String str) -> charactersOf(str).spliterator(),
                    Spliterator.SIZED | Spliterator.DISTINCT | Spliterator.NONNULL,
                    7))
        .expect('a', 'b', 'c', 'd', 'e', 'f', 'g');
  }

  public void testFlatMap_nullStream() {
    SpliteratorTester.of(
            () ->

   * a map serialized by {@link #writeMap(Map, ObjectOutputStream)}, the number of distinct elements
   * in a multiset serialized by {@link #writeMultiset(Multiset, ObjectOutputStream)}, or the number
   * of distinct keys in a multimap serialized by {@link #writeMultimap(Multimap,
   * ObjectOutputStream)}.
   */

    }

    public void test_distinct_nullInput() {
        // Test distinct with null input
        String[] result = invokeDistinct(null);
        assertNotNull(result);
        assertEquals(0, result.length);
        assertSame(StringUtil.EMPTY_STRINGS, result);
    }

    public void test_distinct_emptyArray() {
        // Test distinct with empty array
        String[] input = new String[0];

    JdkBackedSetBuilderImpl(SetBuilderImpl<E> toCopy) {
      super(toCopy); // initializes dedupedElements and distinct
      delegate = Sets.newHashSetWithExpectedSize(distinct);
      for (int i = 0; i < distinct; i++) {
        /*
         * requireNonNull is safe because we ensure that the first `distinct` elements have been
         * populated.
         */
        delegate.add(requireNonNull(dedupedElements[i]));
      }

    return new HashMultiset<>();
  }

  /**
   * Creates a new, empty {@code HashMultiset} with the specified expected number of distinct
   * elements.
   *
   * @param distinctElements the expected number of distinct elements
   * @throws IllegalArgumentException if {@code distinctElements} is negative
   */
  public static <E extends @Nullable Object> HashMultiset<E> create(int distinctElements) {

                    .filter(StringUtil::isNotBlank)
                    .distinct()
                    .toArray(n -> new String[n])));
            entity.setVirtualHosts(split(form.virtualHosts, "\n")
                    .get(stream -> stream.filter(StringUtil::isNotBlank).distinct().map(String::trim).toArray(n -> new String[n])));
            return entity;
        });
    }

    /**

   * a map serialized by {@link #writeMap(Map, ObjectOutputStream)}, the number of distinct elements
   * in a multiset serialized by {@link #writeMultiset(Multiset, ObjectOutputStream)}, or the number
   * of distinct keys in a multimap serialized by {@link #writeMultimap(Multimap,
   * ObjectOutputStream)}.
   */

      ArrayList<V> arrayList = (ArrayList<V>) collection;
      arrayList.trimToSize();
    }
  }

  /**
   * @serialData expectedValuesPerKey, number of distinct keys, and then for each distinct key: the
   *     key, number of values for that key, and the key's values
   */
  @GwtIncompatible
  @J2ktIncompatible
    private void writeObject(ObjectOutputStream stream) throws IOException {

 * to implement the related methods as well. Finally, two collection views are provided: {@link
 * #elementSet} contains the distinct elements of the multiset "with duplicates collapsed", and
 * {@link #entrySet} is similar but contains {@link Entry Multiset.Entry} instances, each providing
 * both a distinct element and the count of that element.
 *
 * <p>In addition to these required methods, implementations of {@code Multiset} are expected to