"content_pl",
        "content_pt",
        "content_pt-br",
        "content_ro",
        "content_ru",
        "content_si",
        "content_sq",
        "content_sv",
        "content_ta",
        "content_te",
        "content_th",
        "content_tl",
        "content_tr",
        "content_uk",
        "content_ur",
        "content_vi",
        "content_zh-cn",

        "content_pl",
        "content_pt",
        "content_pt-br",
        "content_ro",
        "content_ru",
        "content_si",
        "content_sq",
        "content_sv",
        "content_ta",
        "content_te",
        "content_th",
        "content_tl",
        "content_tr",
        "content_uk",
        "content_ur",
        "content_vi",
        "content_zh-cn",

        return new TreeSet<E>(contents);
      }
    },
    UnmodifiableSetImpl {
      @Override
      public <E extends Comparable<E>> Set<E> create(Collection<E> contents) {
        return unmodifiableSet(new HashSet<E>(contents));
      }
    },
    SynchronizedSetImpl {
      @Override
      public <E extends Comparable<E>> Set<E> create(Collection<E> contents) {

During crawling and indexing, Fess:

1. Detects language from document content using Apache Tika
2. Validates against `supported.languages` list
3. Creates language-specific fields (e.g., `content_ja`, `title_en`, `content_sv`)
4. Applies language-specific analyzers for better search results

Configured in `fess_config.properties`:
```properties
indexer.language.fields=content,important_content,title
```

  final transient ObjectCountHashMap<E> contents;
  private final transient int size;

  @LazyInit private transient @Nullable ImmutableSet<E> elementSet;

  RegularImmutableMultiset(ObjectCountHashMap<E> contents) {
    this.contents = contents;
    long size = 0;
    for (int i = 0; i < contents.size(); i++) {
      size += contents.getValue(i);
    }
    this.size = Ints.saturatedCast(size);
  }

      for (List<Integer> contents : SAMPLE_INPUTS) {
        for (int toRemove = 0; toRemove < 10; toRemove++) {
          assertEquals(
              contents.contains(toRemove) && EVEN.apply(toRemove),
              filter(createUnfiltered(contents), EVEN).remove(toRemove));
        }
      }
    }

    public void testContains() {
      for (List<Integer> contents : SAMPLE_INPUTS) {

  public static <E extends @Nullable Object> MinimalSet<E> of(E... contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], asList(contents));
  }

  @SuppressWarnings("unchecked") // empty Object[] as E[]
  public static <E extends @Nullable Object> MinimalSet<E> from(Collection<? extends E> contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], contents);
  }

  public static <E extends @Nullable Object> MinimalSet<E> of(E... contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], asList(contents));
  }

  @SuppressWarnings("unchecked") // empty Object[] as E[]
  public static <E extends @Nullable Object> MinimalSet<E> from(Collection<? extends E> contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], contents);
  }

	}

	var contents []ItemContent
	if err := tx.Find(&contents).Error; err != nil {
		t.Errorf("failed to find contents, got error: %v", err)
	}
	if len(contents) != 3 {
		t.Errorf("expected %d contents, got %d", 3, len(contents))
	}

	// test delete
	if err := tx.Model(&item).Association("Contents").Unscoped().Delete(&contents[0]); err != nil {
		t.Errorf("failed to delete Contents, got error: %v", err)
	}

    return new MinimalCollection<>(Object.class, true, contents);
  }

  // TODO: use this
  public static <E extends @Nullable Object> MinimalCollection<E> ofClassAndContents(
      Class<? super @NonNull E> type, E... contents) {
    return new MinimalCollection<>(type, true, contents);
  }

  private final E[] contents;
  private final Class<? super @NonNull E> type;