}

  private static void testReverse(char[] input, char[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Chars.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(char[] input, int fromIndex, int toIndex, char[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Chars.reverse(input, fromIndex, toIndex);

    T[] empty = reference.length == 0 ? reference : Arrays.copyOf(reference, 0);
    return Arrays.copyOf(empty, length);
  }

  /** Equivalent to Arrays.copyOfRange(source, from, to, arrayOfType.getClass()). */
  static <T extends @Nullable Object> T[] copy(Object[] source, int from, int to, T[] arrayOfType) {
    T[] result = newArray(arrayOfType, to - from);

  private static void testReverse(short[] input, short[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Shorts.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(
      short[] input, int fromIndex, int toIndex, short[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Shorts.reverse(input, fromIndex, toIndex);

    }
  }

  @Override
  public ImmutableMap<C, Map<R, V>> columnMap() {
    // Casts without copying.
    return ImmutableMap.copyOf(columnMap);
  }

  @Override
  public ImmutableMap<R, Map<C, V>> rowMap() {
    // Casts without copying.
    return ImmutableMap.copyOf(rowMap);
  }

  @Override
  public @Nullable V get(@Nullable Object rowKey, @Nullable Object columnKey) {

  private static void testReverse(double[] input, double[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Doubles.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(
      double[] input, int fromIndex, int toIndex, double[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Doubles.reverse(input, fromIndex, toIndex);

    input = Arrays.copyOf(input, input.length);
    SignedBytes.sortDescending(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testSortDescending(
      byte[] input, int fromIndex, int toIndex, byte[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    SignedBytes.sortDescending(input, fromIndex, toIndex);

    } catch (IOException expected) {
      assertSame(thrownException, expected);
    }

    assertTrue(c1.isClosed());
    assertTrue(c2.isClosed());

    ImmutableSet<Throwable> suppressed = ImmutableSet.copyOf(thrownException.getSuppressed());
    assertEquals(2, suppressed.size());

    assertEquals(ImmutableSet.of(c1Exception, c2Exception), suppressed);
  }

  public void testNullCloseable() throws IOException {

    rangeMap.put(Range.open(3, 7), 1);
    rangeMap.put(Range.closed(9, 10), 2);
    rangeMap.put(Range.closed(12, 16), 3);

    RangeMap<Integer, Integer> copy = TreeRangeMap.copyOf(rangeMap);

    assertEquals(rangeMap.asMapOfRanges(), copy.asMapOfRanges());
  }

  public void testCopyOfImmutableRangeMap() {
    ImmutableRangeMap<Integer, Integer> rangeMap =
        ImmutableRangeMap.<Integer, Integer>builder()

  }

  private static void testReverse(int[] input, int[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Ints.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(int[] input, int fromIndex, int toIndex, int[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Ints.reverse(input, fromIndex, toIndex);

  }

  private static void testReverse(byte[] input, byte[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Bytes.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(byte[] input, int fromIndex, int toIndex, byte[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Bytes.reverse(input, fromIndex, toIndex);