list.add(1, "4");
        assertThat(list.get(1), is("4"));
        assertThat(list.get(2), is("2"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testIndexOf() throws Exception {
        list.addLast(null);
        list.addLast("1");
        list.addLast("2");
        list.addLast("3");
        assertThat(list.indexOf(null), is(0));

        assertThat(newArray.length, is(2));
        assertThat(newArray[0], is(1));
        assertThat(newArray[1], is(2));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testIndexOf() throws Exception {
        final String[] array = new String[] { "111", "222", "333", "222" };
        assertThat(ArrayUtil.indexOf(array, "222"), is(1));
        assertThat(ArrayUtil.indexOf(array, "222", 2), is(3));

        map.put("3", null);
        assertThat(map.containsKey("3"), is(true));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testIndexOf() throws Exception {
        assertThat(map.indexOf("test"), is(1));
        assertThat(map.indexOf(null), is(0));
        assertThat(map.indexOf("test3"), is(-1));
    }

    /**
     * @throws Exception

    assertThrows(IndexOutOfBoundsException.class, () -> iia.get(3));

    ImmutableDoubleArray sub = iia.subArray(1, 2);
    assertThrows(IndexOutOfBoundsException.class, () -> sub.get(-1));
  }

  public void testIndexOf() {
    ImmutableDoubleArray iia = ImmutableDoubleArray.of(1, 1, 2, 3, 5, 8);
    assertThat(iia.indexOf(1)).isEqualTo(0);
    assertThat(iia.indexOf(8)).isEqualTo(5);
    assertThat(iia.indexOf(4)).isEqualTo(-1);

    assertThrows(IndexOutOfBoundsException.class, () -> iia.get(3));

    ImmutableIntArray sub = iia.subArray(1, 2);
    assertThrows(IndexOutOfBoundsException.class, () -> sub.get(-1));
  }

  public void testIndexOf() {
    ImmutableIntArray iia = ImmutableIntArray.of(1, 1, 2, 3, 5, 8);
    assertThat(iia.indexOf(1)).isEqualTo(0);
    assertThat(iia.indexOf(8)).isEqualTo(5);
    assertThat(iia.indexOf(4)).isEqualTo(-1);

    assertThat(Bytes.contains(ARRAY234, (byte) 2)).isTrue();
    assertThat(Bytes.contains(ARRAY234, (byte) 3)).isTrue();
    assertThat(Bytes.contains(ARRAY234, (byte) 4)).isTrue();
  }

  public void testIndexOf() {
    assertThat(Bytes.indexOf(EMPTY, (byte) 1)).isEqualTo(-1);
    assertThat(Bytes.indexOf(ARRAY1, (byte) 2)).isEqualTo(-1);
    assertThat(Bytes.indexOf(ARRAY234, (byte) 1)).isEqualTo(-1);

    assertThrows(IndexOutOfBoundsException.class, () -> iia.get(3));

    ImmutableLongArray sub = iia.subArray(1, 2);
    assertThrows(IndexOutOfBoundsException.class, () -> sub.get(-1));
  }

  public void testIndexOf() {
    ImmutableLongArray iia = ImmutableLongArray.of(1, 1, 2, 3, 5, 8);
    assertThat(iia.indexOf(1)).isEqualTo(0);
    assertThat(iia.indexOf(8)).isEqualTo(5);
    assertThat(iia.indexOf(4)).isEqualTo(-1);

    assertThat(Bytes.contains(ARRAY234, (byte) 2)).isTrue();
    assertThat(Bytes.contains(ARRAY234, (byte) 3)).isTrue();
    assertThat(Bytes.contains(ARRAY234, (byte) 4)).isTrue();
  }

  public void testIndexOf() {
    assertThat(Bytes.indexOf(EMPTY, (byte) 1)).isEqualTo(-1);
    assertThat(Bytes.indexOf(ARRAY1, (byte) 2)).isEqualTo(-1);
    assertThat(Bytes.indexOf(ARRAY234, (byte) 1)).isEqualTo(-1);

    assertThat(Chars.contains(ARRAY234, (char) 2)).isTrue();
    assertThat(Chars.contains(ARRAY234, (char) 3)).isTrue();
    assertThat(Chars.contains(ARRAY234, (char) 4)).isTrue();
  }

  public void testIndexOf() {
    assertThat(Chars.indexOf(EMPTY, (char) 1)).isEqualTo(-1);
    assertThat(Chars.indexOf(ARRAY1, (char) 2)).isEqualTo(-1);
    assertThat(Chars.indexOf(ARRAY234, (char) 1)).isEqualTo(-1);

    assertThat(Chars.contains(ARRAY234, (char) 2)).isTrue();
    assertThat(Chars.contains(ARRAY234, (char) 3)).isTrue();
    assertThat(Chars.contains(ARRAY234, (char) 4)).isTrue();
  }

  public void testIndexOf() {
    assertThat(Chars.indexOf(EMPTY, (char) 1)).isEqualTo(-1);
    assertThat(Chars.indexOf(ARRAY1, (char) 2)).isEqualTo(-1);
    assertThat(Chars.indexOf(ARRAY234, (char) 1)).isEqualTo(-1);