AtomicDouble.class);
  }

  @SuppressWarnings("unchecked") // functor classes have no type parameters
  public void testGet_functors() {
    assertEquals(0, ArbitraryInstances.get(Comparator.class).compare("abc", 123));
    assertTrue(ArbitraryInstances.get(Predicate.class).apply("abc"));
    assertTrue(ArbitraryInstances.get(Equivalence.class).equivalent(1, 1));
    assertFalse(ArbitraryInstances.get(Equivalence.class).equivalent(1, 2));

    assertThat(Ints.join(",", ARRAY1)).isEqualTo("1");
    assertThat(Ints.join(",", (int) 1, (int) 2)).isEqualTo("1,2");
    assertThat(Ints.join("", (int) 1, (int) 2, (int) 3)).isEqualTo("123");
  }

  public void testLexicographicalComparator() {
    List<int[]> ordered =
        Arrays.asList(
            new int[] {},
            new int[] {LEAST},
            new int[] {LEAST, LEAST},

    assertThat(Chars.join(",", EMPTY)).isEmpty();
    assertThat(Chars.join(",", '1')).isEqualTo("1");
    assertThat(Chars.join(",", '1', '2')).isEqualTo("1,2");
    assertThat(Chars.join("", '1', '2', '3')).isEqualTo("123");
  }

  public void testLexicographicalComparator() {
    List<char[]> ordered =
        Arrays.asList(
            new char[] {},
            new char[] {LEAST},
            new char[] {LEAST, LEAST},

    Multimap<String, Integer> unmodifiable =
        prepareUnmodifiableTests(multimap, permitsDuplicates, nullKey, nullValue);

    UnmodifiableCollectionTests.assertMultimapIsUnmodifiable(unmodifiable, "test", 123);

    assertUnmodifiableIterableInTandem(unmodifiable.keys(), multimap.keys());

    assertUnmodifiableIterableInTandem(unmodifiable.keySet(), multimap.keySet());