expectContents();
  }

  // retainAll(null)

  /*
   * AbstractCollection fails the retainAll(null) test when the subject
   * collection is empty, but we'd still like to test retainAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.
   */

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)

     * @param dataMap additional data map (not currently used)
     * @return the normalized title, or empty string if title is null
     */
    public String getTitle(final ResponseData responseData, final String title, final Map<String, Object> dataMap) {
        if (title == null) {
            return StringUtil.EMPTY; // empty
        }

        final int[] spaceChars = getSpaceChars();

     *
     * @param name
     *            The resource name. Must not be {@literal null} or an empty string.
     * @return An iterator of URL objects for the resources. If no resources are found, the iterator will be empty.
     *         Resources that the class loader does not have access to will not be included.
     * @see java.lang.ClassLoader#getResources(String)
     */

        if (values.length == 0) {
            // invalid?
            return new PathInfo(StringUtil.EMPTY, StringUtil.EMPTY);
        }
        if (values.length == 1) {
            return new PathInfo(StringUtil.EMPTY, values[0]);
        }
        final StringBuilder buf = new StringBuilder();
        for (int i = 0; i < values.length - 1; i++) {

 * @since 22.0
 */
@GwtCompatible
@Immutable
public final class ImmutableLongArray implements Serializable {
  private static final ImmutableLongArray EMPTY = new ImmutableLongArray(new long[0]);

  /** Returns the empty array. */
  public static ImmutableLongArray of() {
    return EMPTY;
  }

  /** Returns an immutable array containing a single value. */
  public static ImmutableLongArray of(long e0) {

 * @since 22.0
 */
@GwtCompatible
@Immutable
public final class ImmutableIntArray implements Serializable {
  private static final ImmutableIntArray EMPTY = new ImmutableIntArray(new int[0]);

  /** Returns the empty array. */
  public static ImmutableIntArray of() {
    return EMPTY;
  }

  /** Returns an immutable array containing a single value. */
  public static ImmutableIntArray of(int e0) {

  }

  public void testEmptiesFirst() {
    Optional<String> empty = Optional.empty();
    Optional<String> abc = Optional.of("abc");
    Optional<String> z = Optional.of("z");

    Comparator<Optional<String>> comparator = emptiesFirst(comparing(String::length));
    testComparator(comparator, empty, z, abc);

    // Just demonstrate that no explicit type parameter is required

            rankFusionProcessor.init();

            if (rankFusionProcessor.search(query, new TestSearchRequestParams(0, pageSize, 0),
                    OptionalThing.empty()) instanceof QueryResponseList list) {
                assertEquals(pageSize, list.size());
                assertEquals(allRecordCount, list.getAllRecordCount());
                assertEquals(100, list.getAllPageCount());

        fileTypeHelper.add("", "empty");
        assertEquals("empty", fileTypeHelper.get(""));
    }

    public void test_add_withNullFiletype() {
        fileTypeHelper.add("test/null", null);
        assertEquals("others", fileTypeHelper.get("test/null"));
    }

    public void test_add_withEmptyFiletype() {
        fileTypeHelper.add("test/empty", "");

  public void testConcat() {
    assertThat(Doubles.concat()).isEqualTo(EMPTY);
    assertThat(Doubles.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Doubles.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Doubles.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Doubles.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Doubles.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);