"it-trace.ch",
          "cool.dk",
          "cool.co.uk",
          "cool.de",
          "cool.es",
          "cool\uFF61fr", // Alternate dot character
          "cool.nl",
          "members.blah.nl.",
          "cool.se",
          "utenti.blah.it",
          "kt.co",
          "a\u7f51\u7edcA.\u7f51\u7edc.Cn" // "a网络A.网络.Cn"
          );

          "it-trace.ch",
          "cool.dk",
          "cool.co.uk",
          "cool.de",
          "cool.es",
          "cool\uFF61fr", // Alternate dot character
          "cool.nl",
          "members.blah.nl.",
          "cool.se",
          "utenti.blah.it",
          "kt.co",
          "a\u7f51\u7edcA.\u7f51\u7edc.Cn" // "a网络A.网络.Cn"
          );

   * of each element is the <i>maximum</i> of its counts in the two backing multisets. The iteration
   * order of the returned multiset matches that of the element set of {@code multiset1} followed by
   * the members of the element set of {@code multiset2} that are not contained in {@code
   * multiset1}, with repeated occurrences of the same element appearing consecutively.
   *

   * http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/test/tck/AbstractExecutorServiceTest.java?revision=1.30
   * which contained the following notice:
   *
   * Written by Doug Lea with assistance from members of JCP JSR-166 Expert Group and released to
   * the public domain, as explained at http://creativecommons.org/publicdomain/zero/1.0/
   *
   * Other contributors include Andrew Wright, Jeffrey Hayes, Pat Fisher, Mike Judd.

    // Serialization invokes writeObject only when it's private.
    // The SynchronizedObject subclasses don't need a writeObject method since
    // they don't contain any non-transient member variables, while the
    // following writeObject() handles the SynchronizedObject members.

    @GwtIncompatible // java.io.ObjectOutputStream
    @J2ktIncompatible
    private void writeObject(ObjectOutputStream stream) throws IOException {

   *
   * @param collection the presumed-immutable collection
   * @param sampleElement an element of the same type as that contained by {@code collection}.
   *     {@code collection} may or may not have {@code sampleElement} as a member.
   */
  public static <E extends @Nullable Object> void assertCollectionIsUnmodifiable(
      Collection<E> collection, E sampleElement) {
    Collection<E> siblingCollection = new ArrayList<>();

    Ordering<Number> i = numbers.compound(objects.compound(objects));
    Ordering<Number> j = objects.compound(numbers.compound(objects)); // bad IDEA
    Ordering<Number> k = objects.compound(objects.compound(numbers));

    // You can also arbitrarily assign a more restricted type - not an intended
    // feature, exactly, but unavoidable (I think) and harmless
    Ordering<Integer> l = objects.compound(numbers);

    Ordering<Number> i = numbers.compound(objects.compound(objects));
    Ordering<Number> j = objects.compound(numbers.compound(objects)); // bad IDEA
    Ordering<Number> k = objects.compound(objects.compound(numbers));

    // You can also arbitrarily assign a more restricted type - not an intended
    // feature, exactly, but unavoidable (I think) and harmless
    Ordering<Integer> l = objects.compound(numbers);

    AtomicInteger numbersCloseCount = new AtomicInteger();
    Stream<Integer> numbers = Stream.of(1, 2, 3).onClose(numbersCloseCount::incrementAndGet);

    Stream<String> zipped = Streams.zip(letters, numbers, (a, b) -> a + ":" + b);

    zipped.close();

    assertThat(lettersCloseCount.get()).isEqualTo(1);

    }

    /**
     * The number of permutations with repeated elements is calculated as follows:
     *
     * <ul>
     *   <li>For an empty list, it is 1 (base case).
     *   <li>When r numbers are added to a list of n-r elements, the number of permutations is
     *       increased by a factor of (n choose r).
     * </ul>
     */
    private static <E> int calculateSize(