* @throws NullPointerException if any element in the stream is {@code null}.
   * @return {@code Optional.of(onlyElement)} if the stream has exactly one element (must not be
   *     {@code null}) and returns {@code Optional.empty()} if it has none.
   */
  @SuppressWarnings("unchecked")
  public static <T> Collector<T, ?, Optional<T>> toOptional() {
    return (Collector) TO_OPTIONAL;
  }

     * @param url The URL.
     * @return The host on file.
     */
    protected String getHostOnFile(final String url) {
        if (StringUtil.isBlank(url)) {
            return StringUtil.EMPTY; // empty
        }

        if (url.startsWith("file:////")) {
            final String value = decodeUrlAsName(url.substring(9), true);
            final int pos = value.indexOf('/');
            if (pos > 0) {

    assertTrue(collection.contains(e0()));
  }

  /*
   * AbstractCollection fails the removeAll(null) test when the subject
   * collection is empty, but we'd still like to test removeAll(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)

  }

  public static <E extends Enum<E>> EnumMultiset<E> create(Iterable<E> elements) {
    Iterator<E> iterator = elements.iterator();
    checkArgument(iterator.hasNext(), "EnumMultiset constructor passed empty Iterable");
    EnumMap<E, Count> map = new EnumMap<>(getDeclaringClassOrObjectForJ2cl(iterator.next()));
    EnumMultiset<E> multiset = new EnumMultiset<>(map);
    Iterables.addAll(multiset, elements);
    return multiset;

        long allRecordCount = 100L;
        String allRecordCountRelation = "eq";
        long queryTime = 50L;
        boolean partialResults = false;
        Aggregations aggregations = InternalAggregations.EMPTY;
        FacetResponse facetResponse = new FacetResponse(aggregations);

        SearchResult result =

    assertEquals(ASCII.length(), CharStreams.exhaust(reader));
    assertEquals(-1, reader.read());
    assertEquals(0, CharStreams.exhaust(reader));

    Reader empty = new StringReader("");
    assertEquals(0, CharStreams.exhaust(empty));
    assertEquals(-1, empty.read());
  }

  public void testExhaust_readable() throws IOException {
    CharBuffer buf = CharBuffer.wrap(ASCII);

    assertEquals(ASCII.length(), CharStreams.exhaust(reader));
    assertEquals(-1, reader.read());
    assertEquals(0, CharStreams.exhaust(reader));

    Reader empty = new StringReader("");
    assertEquals(0, CharStreams.exhaust(empty));
    assertEquals(-1, empty.read());
  }

  public void testExhaust_readable() throws IOException {
    CharBuffer buf = CharBuffer.wrap(ASCII);

    /**
     * Returns an empty OptionalThing for login manager since API actions
     * use token-based authentication instead of traditional session-based login.
     *
     * @return empty OptionalThing indicating no login manager is used
     */
    @Override
    protected OptionalThing<LoginManager> myLoginManager() {
        return OptionalThing.empty();
    }

    /**

     */
    public OptionalEntity<CharMappingFile> getCharMappingFile(final String dictId) {
        return dictionaryManager.getDictionaryFile(dictId)
                .filter(CharMappingFile.class::isInstance)
                .map(file -> OptionalEntity.of((CharMappingFile) file))
                .orElse(OptionalEntity.empty());
    }

    /**

    }

    @Test
    @DisplayName("byte[] ctor: empty token throws PACDecodingException with clear message")
    void byteArrayConstructor_emptyToken_throws() {
        // Arrange
        byte[] empty = new byte[0];

        // Act + Assert
        PACDecodingException ex = assertThrows(PACDecodingException.class, () -> new KerberosApRequest(empty, new KerberosKey[0]));