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);
  }

import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER;
import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE;
import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.collect.testing.IteratorTester;

            (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)));
    }

    Iterable<?> b;

    // A few elements.
    a = asList(4, 8, 15, 16, 23, 42);
    b = asList(4, 8, 15, 16, 23, 42);
    assertTrue(elementsEqual(a, b));

    // An element differs.
    a = asList(4, 8, 15, 12, 23, 42);
    b = asList(4, 8, 15, 16, 23, 42);
    assertFalse(elementsEqual(a, b));

    // null versus non-null.
    a = Arrays.<@Nullable Integer>asList(4, 8, 15, null, 23, 42);

  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() {

            ListTestSuiteBuilder.using(new ShortsAsListTailSubListGenerator())
                .named("Shorts.asList, tail subList"),
            ListTestSuiteBuilder.using(new ShortsAsListMiddleSubListGenerator())
                .named("Shorts.asList, middle subList"));

    TestSuite suite = new TestSuite();
    for (ListTestSuiteBuilder<Short> builder : builders) {
      suite.addTest(
          builder

            ListTestSuiteBuilder.using(new LongsAsListTailSubListGenerator())
                .named("Longs.asList, tail subList"),
            ListTestSuiteBuilder.using(new LongsAsListMiddleSubListGenerator())
                .named("Longs.asList, middle subList"));

    TestSuite suite = new TestSuite();
    for (ListTestSuiteBuilder<Long> builder : builders) {
      suite.addTest(
          builder

            ListTestSuiteBuilder.using(new ShortsAsListTailSubListGenerator())
                .named("Shorts.asList, tail subList"),
            ListTestSuiteBuilder.using(new ShortsAsListMiddleSubListGenerator())
                .named("Shorts.asList, middle subList"));

    TestSuite suite = new TestSuite();
    for (ListTestSuiteBuilder<Short> builder : builders) {
      suite.addTest(
          builder

    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);
  }

    assertThat(result).asList().containsExactly("foo", "bar", "baz").inOrder();
  }

  public void testAppendZeroElements() {
    String[] result = ObjectArrays.concat(new String[] {}, "foo");
    assertThat(result).asList().contains("foo");
  }

  public void testAppendOneElement() {
    String[] result = ObjectArrays.concat(new String[] {"foo"}, "bar");