assertEquals(HashMultiset.create(asList("a", "b", "a", "c")), multiset);
  }

  public void testBuilderAddAll() {
    List<String> a = asList("a", "b");
    List<String> b = asList("c", "d");
    ImmutableMultiset<String> multiset =
        new ImmutableMultiset.Builder<String>().addAll(a).addAll(b).build();
    assertEquals(HashMultiset.create(asList("a", "b", "c", "d")), multiset);
  }

    assertEquals(HashMultiset.create(asList("a", "b", "a", "c")), multiset);
  }

  public void testBuilderAddAll() {
    List<String> a = asList("a", "b");
    List<String> b = asList("c", "d");
    ImmutableMultiset<String> multiset =
        new ImmutableMultiset.Builder<String>().addAll(a).addAll(b).build();
    assertEquals(HashMultiset.create(asList("a", "b", "c", "d")), multiset);
  }

    assertEquals(asList("a", "b", "a", "c"), list);
  }

  public void testBuilderAddAll_iterable() {
    List<String> a = asList("a", "b");
    List<String> b = asList("c", "d");
    ImmutableList<String> list = new ImmutableList.Builder<String>().addAll(a).addAll(b).build();
    assertEquals(asList("a", "b", "c", "d"), list);
    b.set(0, "f");
    assertEquals(asList("a", "b", "c", "d"), list);
  }

            (K k, V v) -> {
              int index = keys().asList().indexOf(k);
              return values().asList().get(index + 1);
            });
    List<Entry<K, V>> expectedEntries = new ArrayList<>();
    for (Entry<K, V> entry : getSampleEntries()) {
      int index = keys().asList().indexOf(entry.getKey());
      expectedEntries.add(Helpers.mapEntry(entry.getKey(), values().asList().get(index + 1)));
    }

    assertTrue(set.containsAll(asList("b")));
    assertTrue(set.containsAll(asList("b", "b")));
    assertTrue(set.containsAll(asList("b", "f")));
    assertTrue(set.containsAll(asList("b", "f", "a")));
    assertFalse(set.containsAll(asList("d")));
    assertFalse(set.containsAll(asList("z")));
    assertFalse(set.containsAll(asList("b", "d")));
    assertFalse(set.containsAll(asList("f", "d", "a")));
  }

  public void testConcatUnmodifiable() {
    new IteratorTester<Integer>(
        5, UNMODIFIABLE, asList(1, 2), IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override
      protected Iterator<Integer> newTargetIterator() {
        return Iterators.concat(
            asList(1).iterator(), Arrays.<Integer>asList().iterator(), asList(2).iterator());
      }
    }.test();
  }

  public void testConcatPartiallyAdvancedSecond() {

    assertEquals(asList("a", "b", "a", "c"), list);
  }

  public void testBuilderAddAll_iterable() {
    List<String> a = asList("a", "b");
    List<String> b = asList("c", "d");
    ImmutableList<String> list = new ImmutableList.Builder<String>().addAll(a).addAll(b).build();
    assertEquals(asList("a", "b", "c", "d"), list);
    b.set(0, "f");
    assertEquals(asList("a", "b", "c", "d"), list);
  }

  }

  public void testIsOrdered() {
    assertFalse(numberOrdering.isOrdered(asList(5, 3, 0, 9)));
    assertFalse(numberOrdering.isOrdered(asList(0, 5, 3, 9)));
    assertTrue(numberOrdering.isOrdered(asList(0, 3, 5, 9)));
    assertTrue(numberOrdering.isOrdered(asList(0, 0, 3, 3)));
    assertTrue(numberOrdering.isOrdered(asList(0, 3)));
    assertTrue(numberOrdering.isOrdered(singleton(1)));

  }

  public void testIsOrdered() {
    assertFalse(numberOrdering.isOrdered(asList(5, 3, 0, 9)));
    assertFalse(numberOrdering.isOrdered(asList(0, 5, 3, 9)));
    assertTrue(numberOrdering.isOrdered(asList(0, 3, 5, 9)));
    assertTrue(numberOrdering.isOrdered(asList(0, 0, 3, 3)));
    assertTrue(numberOrdering.isOrdered(asList(0, 3)));
    assertTrue(numberOrdering.isOrdered(singleton(1)));

    assertEquals(HashMultiset.create(asList("a", "b", "a", "c")), multiset);
  }

  public void testBuilderAddAll() {
    List<String> a = asList("a", "b");
    List<String> b = asList("c", "d");
    ImmutableSortedMultiset<String> multiset =
        ImmutableSortedMultiset.<String>naturalOrder().addAll(a).addAll(b).build();
    assertEquals(HashMultiset.create(asList("a", "b", "c", "d")), multiset);
  }