*
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in
 * a {@code Map<R, Map<C, V>>}. A method call like {@code column(columnKey).get(rowKey)} still runs

    assertThat(MANY_VALUES_STATS_ITERABLE.sum())
        .isWithin(ALLOWED_ERROR)
        .of(MANY_VALUES_MEAN * MANY_VALUES_COUNT);
    assertThat(MANY_VALUES_STATS_ITERATOR.sum())
        .isWithin(ALLOWED_ERROR)
        .of(MANY_VALUES_MEAN * MANY_VALUES_COUNT);
    assertThat(MANY_VALUES_STATS_SNAPSHOT.sum())
        .isWithin(ALLOWED_ERROR)
        .of(MANY_VALUES_MEAN * MANY_VALUES_COUNT);

        .of(INTEGER_MANY_VALUES_MEAN * INTEGER_MANY_VALUES_COUNT);
    assertThat(longManyValuesAccumulatorByAddAllIterator.sum())
        .isWithin(ALLOWED_ERROR * LONG_MANY_VALUES_MEAN)
        .of(LONG_MANY_VALUES_MEAN * LONG_MANY_VALUES_COUNT);
    assertThat(longManyValuesAccumulatorByAddAllVarargs.sum())
        .isWithin(ALLOWED_ERROR * LONG_MANY_VALUES_MEAN)
        .of(LONG_MANY_VALUES_MEAN * LONG_MANY_VALUES_COUNT);
  }

        .addEqualityGroup(
            new PairedStats(MANY_VALUES_STATS_ITERABLE, MANY_VALUES_STATS_ITERABLE, 1.23))
        .addEqualityGroup(new PairedStats(TWO_VALUES_STATS, MANY_VALUES_STATS_ITERABLE, 1.23))
        .addEqualityGroup(new PairedStats(MANY_VALUES_STATS_ITERABLE, ONE_VALUE_STATS, 1.23))
        .addEqualityGroup(

        .addEqualityGroup(
            new PairedStats(MANY_VALUES_STATS_ITERABLE, MANY_VALUES_STATS_ITERABLE, 1.23))
        .addEqualityGroup(new PairedStats(TWO_VALUES_STATS, MANY_VALUES_STATS_ITERABLE, 1.23))
        .addEqualityGroup(new PairedStats(MANY_VALUES_STATS_ITERABLE, ONE_VALUE_STATS, 1.23))
        .addEqualityGroup(

  /** Returns an immutable array containing the given values, in order. */
  public static ImmutableIntArray copyOf(int[] values) {
    return values.length == 0 ? EMPTY : new ImmutableIntArray(Arrays.copyOf(values, values.length));
  }

  /** Returns an immutable array containing the given values, in order. */
  public static ImmutableIntArray copyOf(Collection<Integer> values) {

  public static ImmutableDoubleArray copyOf(double[] values) {
    return values.length == 0
        ? EMPTY
        : new ImmutableDoubleArray(Arrays.copyOf(values, values.length));
  }

  /** Returns an immutable array containing the given values, in order. */
  public static ImmutableDoubleArray copyOf(Collection<Double> values) {

  }

  /** constructor with array is of same size and has all elements */
  public void testConstructor2() {
    AtomicDoubleArray aa = new AtomicDoubleArray(VALUES);
    assertEquals(VALUES.length, aa.length());
    for (int i = 0; i < VALUES.length; i++) {
      assertBitEquals(VALUES[i], aa.get(i));
    }
  }

  /** constructor with empty array has size 0 and contains no elements */
  public void testConstructorEmptyArray() {

  }

  /** constructor with array is of same size and has all elements */
  public void testConstructor2() {
    AtomicDoubleArray aa = new AtomicDoubleArray(VALUES);
    assertEquals(VALUES.length, aa.length());
    for (int i = 0; i < VALUES.length; i++) {
      assertBitEquals(VALUES[i], aa.get(i));
    }
  }

  /** constructor with empty array has size 0 and contains no elements */
  public void testConstructorEmptyArray() {

  @Override
  protected void assertGet(K key, V... values) {
    assertGet(key, Arrays.asList(values));
  }

  @Override
  protected void assertGet(K key, Collection<? extends V> values) {
    assertEqualInOrder(values, multimap().get(key));

    if (!values.isEmpty()) {
      assertEqualInOrder(values, multimap().asMap().get(key));
      assertFalse(multimap().isEmpty());
    } else {