}

  public void testContainsColumn() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertTrue(table.containsColumn(1));
    assertTrue(table.containsColumn(3));
    assertFalse(table.containsColumn(2));
    assertFalse(table.containsColumn(null));
  }

  public void testContainsValue() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');

  }

  public void testContainsColumn() {
    for (ImmutableTable<Character, Integer, String> testInstance : getTestInstances()) {
      assertTrue(testInstance.containsColumn(1));
      assertTrue(testInstance.containsColumn(2));
      assertFalse(testInstance.containsColumn(3));
    }
  }

  public void testContainsRow() {
    for (ImmutableTable<Character, Integer, String> testInstance : getTestInstances()) {

      // requireNonNull is safe because of the containsColumn check.
      return containsColumn(key) ? column((C) requireNonNull(key)) : null;
    }

    @Override
    public boolean containsKey(@Nullable Object key) {
      return containsColumn(key);
    }

    @Override
    public @Nullable Map<R, V> remove(@Nullable Object key) {
      return containsColumn(key) ? removeColumn(key) : null;
    }

    assertFalse(testTable.contains('A', 1));
    assertFalse(testTable.contains('A', 2));
  }

  public void testContainsColumn() {
    assertTrue(testTable.containsColumn(1));
    assertFalse(testTable.containsColumn(2));
  }

  public void testContainsRow() {
    assertTrue(testTable.containsRow('a'));
    assertFalse(testTable.containsRow('A'));
  }

  public void testContainsValue() {

      assertTrue(Thread.holdsLock(mutex));
      return delegate.contains(rowKey, columnKey);
    }

    @Override
    public boolean containsColumn(Object columnKey) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.containsColumn(columnKey);
    }

    @Override
    public boolean containsRow(Object rowKey) {
      assertTrue(Thread.holdsLock(mutex));

    this(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
  }

  @Override
  public ImmutableMap<R, V> column(C columnKey) {
    checkNotNull(columnKey);
    return containsColumn(columnKey)
        ? ImmutableMap.of(singleRowKey, singleValue)
        : ImmutableMap.<R, V>of();
  }

  @Override
  public ImmutableMap<C, Map<R, V>> columnMap() {

    implements Table<R, C, V> {

  @Override
  public boolean containsRow(@Nullable Object rowKey) {
    return Maps.safeContainsKey(rowMap(), rowKey);
  }

  @Override
  public boolean containsColumn(@Nullable Object columnKey) {
    return Maps.safeContainsKey(columnMap(), columnKey);
  }

  @Override
  public Set<R> rowKeySet() {
    return rowMap().keySet();
  }

  @Override

    implements Table<R, C, V> {

  @Override
  public boolean containsRow(@Nullable Object rowKey) {
    return Maps.safeContainsKey(rowMap(), rowKey);
  }

  @Override
  public boolean containsColumn(@Nullable Object columnKey) {
    return Maps.safeContainsKey(columnMap(), columnKey);
  }

  @Override
  public Set<R> rowKeySet() {
    return rowMap().keySet();
  }

  @Override

      return original.contains(columnKey, rowKey);
    }

    @Override
    public boolean containsColumn(@Nullable Object columnKey) {
      return original.containsRow(columnKey);
    }

    @Override
    public boolean containsRow(@Nullable Object rowKey) {
      return original.containsColumn(rowKey);
    }

    @Override
    public boolean containsValue(@Nullable Object value) {

  public boolean contains(@Nullable Object rowKey, @Nullable Object columnKey) {
    return containsRow(rowKey) && containsColumn(columnKey);
  }

  /**
   * Returns {@code true} if the provided column key is among the column keys provided when the
   * table was constructed.
   */
  @Override
  public boolean containsColumn(@Nullable Object columnKey) {
    return columnKeyToIndex.containsKey(columnKey);
  }

  /**