assertThat(iia.lastIndexOf(1)).isEqualTo(1);
    assertThat(iia.lastIndexOf(8)).isEqualTo(5);
    assertThat(iia.lastIndexOf(4)).isEqualTo(-1);
    assertThat(ImmutableDoubleArray.of(13).lastIndexOf(13)).isEqualTo(0);
    assertThat(ImmutableDoubleArray.of().lastIndexOf(21)).isEqualTo(-1);
    assertThat(iia.subArray(1, 5).lastIndexOf(1)).isEqualTo(0);
  }

  public void testContains() {

    assertThat(Bytes.lastIndexOf(EMPTY, (byte) 1)).isEqualTo(-1);
    assertThat(Bytes.lastIndexOf(ARRAY1, (byte) 2)).isEqualTo(-1);
    assertThat(Bytes.lastIndexOf(ARRAY234, (byte) 1)).isEqualTo(-1);
    assertThat(Bytes.lastIndexOf(new byte[] {(byte) -1}, (byte) -1)).isEqualTo(0);
    assertThat(Bytes.lastIndexOf(ARRAY234, (byte) 2)).isEqualTo(0);
    assertThat(Bytes.lastIndexOf(ARRAY234, (byte) 3)).isEqualTo(1);

  public void testLastIndexOf() {
    assertThat(Doubles.lastIndexOf(EMPTY, 1.0)).isEqualTo(-1);
    assertThat(Doubles.lastIndexOf(ARRAY1, 2.0)).isEqualTo(-1);
    assertThat(Doubles.lastIndexOf(ARRAY234, 1.0)).isEqualTo(-1);
    assertThat(Doubles.lastIndexOf(new double[] {-1.0}, -1.0)).isEqualTo(0);
    assertThat(Doubles.lastIndexOf(ARRAY234, 2.0)).isEqualTo(0);
    assertThat(Doubles.lastIndexOf(ARRAY234, 3.0)).isEqualTo(1);

    assertThat(Chars.lastIndexOf(EMPTY, (char) 1)).isEqualTo(-1);
    assertThat(Chars.lastIndexOf(ARRAY1, (char) 2)).isEqualTo(-1);
    assertThat(Chars.lastIndexOf(ARRAY234, (char) 1)).isEqualTo(-1);
    assertThat(Chars.lastIndexOf(new char[] {(char) -1}, (char) -1)).isEqualTo(0);
    assertThat(Chars.lastIndexOf(ARRAY234, (char) 2)).isEqualTo(0);
    assertThat(Chars.lastIndexOf(ARRAY234, (char) 3)).isEqualTo(1);

    assertEquals(size - 1, copy.lastIndexOf(list.get(size - 1)));
    assertEquals(size - 2, head.lastIndexOf(list.get(size - 2)));
    assertEquals(size - 2, tail.lastIndexOf(list.get(size - 1)));
    // The following assumes all elements are distinct.
    assertEquals(0, copy.lastIndexOf(list.get(0)));
    assertEquals(0, head.lastIndexOf(list.get(0)));
    assertEquals(0, tail.lastIndexOf(list.get(1)));

    assertThat(Booleans.lastIndexOf(EMPTY, false)).isEqualTo(-1);
    assertThat(Booleans.lastIndexOf(ARRAY_FALSE, true)).isEqualTo(-1);
    assertThat(Booleans.lastIndexOf(ARRAY_FALSE_FALSE, true)).isEqualTo(-1);
    assertThat(Booleans.lastIndexOf(ARRAY_FALSE, false)).isEqualTo(0);
    assertThat(Booleans.lastIndexOf(ARRAY_FALSE_TRUE, false)).isEqualTo(0);
    assertThat(Booleans.lastIndexOf(ARRAY_FALSE_TRUE, true)).isEqualTo(1);

    assertThat(iia.lastIndexOf(1)).isEqualTo(1);
    assertThat(iia.lastIndexOf(8)).isEqualTo(5);
    assertThat(iia.lastIndexOf(4)).isEqualTo(-1);
    assertThat(ImmutableLongArray.of(13).lastIndexOf(13)).isEqualTo(0);
    assertThat(ImmutableLongArray.of().lastIndexOf(21)).isEqualTo(-1);
    assertThat(iia.subArray(1, 5).lastIndexOf(1)).isEqualTo(0);
  }

  public void testContains() {

  public void testLastIndexOf() {
    assertThat(Ints.lastIndexOf(EMPTY, (int) 1)).isEqualTo(-1);
    assertThat(Ints.lastIndexOf(ARRAY1, (int) 2)).isEqualTo(-1);
    assertThat(Ints.lastIndexOf(ARRAY234, (int) 1)).isEqualTo(-1);
    assertThat(Ints.lastIndexOf(new int[] {(int) -1}, (int) -1)).isEqualTo(0);
    assertThat(Ints.lastIndexOf(ARRAY234, (int) 2)).isEqualTo(0);
    assertThat(Ints.lastIndexOf(ARRAY234, (int) 3)).isEqualTo(1);

   *     such index exists.
   */
  public static int lastIndexOf(boolean[] array, boolean target) {
    return lastIndexOf(array, target, 0, array.length);
  }

  // TODO(kevinb): consider making this public
  private static int lastIndexOf(boolean[] array, boolean target, int start, int end) {
    for (int i = end - 1; i >= start; i--) {
      if (array[i] == target) {

   *     such index exists.
   */
  public static int lastIndexOf(boolean[] array, boolean target) {
    return lastIndexOf(array, target, 0, array.length);
  }

  // TODO(kevinb): consider making this public
  private static int lastIndexOf(boolean[] array, boolean target, int start, int end) {
    for (int i = end - 1; i >= start; i--) {
      if (array[i] == target) {